http://www.mycomputingart.com Articles about computing. en http://www.mycomputingart.com/2008/09/26#z24.openSP4270 <ul> <li><a href="http://www.mycomputingart.com/hardware/./z24.openSP4270.html#intro">Introduction</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.openSP4270.html#steps">Steps</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.openSP4270.html#pictures">Pictures</a></li> </ul> <p><a href="http://www.mycomputingart.com/hardware/z24.openSP4270.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2008/09/26#z24.GA-MA790FX-DS5 <ul> <li><a href="http://www.mycomputingart.com/hardware/./z24.GA-MA790FX-DS5.html#intro">Introduction</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.GA-MA790FX-DS5.html#package">Package</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.GA-MA790FX-DS5.html#pictures">Pictures</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.GA-MA790FX-DS5.html#info">Info</a></li> </ul> <p><a href="http://www.mycomputingart.com/hardware/z24.GA-MA790FX-DS5.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2008/08/21#Z24.restoreprofile <p>While I was logging on from a remote console through RDP I've got a message telling me that the user profile is damaged. I was able to log on and I lost all the settings: desktop, menu and all the settings of the various applications, as if my user had just been created; that means, the user registry was corrupted and it has been replaced with the default user registry.</p> <p>Event Viewer reported these error messages:</p> <p class="error_message">DETAIL - The process cannot access the file because it is being used by another process. for C:\Documents and Settings\Z24\ntuser.dat</p> <p class="error_message">Windows has backed up this user's profile. Windows will automatically try to use the backed up profile the next time this user logs on.</p> <p class="error_message">Windows cannot find the local profile and is logging you on with a temporary profile. Changes you make to this profile will be lost when you log off.</p> I don't know what would have happened logging off and on again (the original profile would have been restored automatically?), by the way I recovered it this way:<br/> <ul> <li>I created a new user, just to be sure to be able to logon if something went bad</li> <li>I rebooted into linux</li> <li>I copied the user registry file <code>C:\System Volume Information\_restore{<i>xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx</i>}\RP<i>yy</i>\snapshot\_REGISTRY_USER_NTUSER_<i>S-z-z-zz-zzzzzzzzzz-zzzzzzzzzz-zzzzzzzzz-zzzz</i></code> to <code>C:\Documents and Settings\<i>USERNAME</i>\ntuser.dat</code>:<br/> the <i>x</i>'s in the restore path are hex digits and <i>yy</i> is a number: the exact restore path where to look in should be the one with the most recent date and time before the date and time of the unsuccessful logon, i.e. yesterday's date if the error happened at today's first logon;<br/> <code><i>S-z-z-zz...</i></code> is the user's SID (see <a href="http://www.mycomputingart.com/windows/./Z24.sid.html">how to associate username and SID</a>);<br/> and <code><i>USERNAME</i></code> is the username</li> <li>I also copied the file <code>_REGISTRY_USER_USRCLASS_S-z-z-zz-zzzzzzzzzz-zzzzzzzzzz-zzzzzzzzz-zzzz</code> from the same path to <code>C:\Documents and Settings\<i>USERNAME</i>\Local Settings\Application Data\Microsoft\Windows\UsrClass.dat</code></li> </ul> At the next logon my windows settings and my applications settings came back! http://www.mycomputingart.com/2008/08/21#Z24.sid <p>To know which is the username associated with a known SID (Security Identifier), open the registry (regedit.exe) at this location: <code>HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList</code>.</p> <p><img src="http://www.mycomputingart.com/images/regedit_sid.jpg" alt="Registry editor with SID keys (62k)"></p> <p>Each SID key has a <code>ProfileImagePath</code> string whose value is the user path which contains the username.<br/> To know which is the SID associated with a known username, select the <code>ProfileList</code> key and search the username.</p> <p>There is also a <a href="http://technet.microsoft.com/en-us/sysinternals/bb897417.aspx">SysInternals command-line utility</a> which shows the SID associated with a known username:<br/> <pre>C:\>psgetsid Z24 PsGetSid v1.43 - Translates SIDs to names and vice versa Copyright (C) 1999-2006 Mark Russinovich Sysinternals - www.sysinternals.com SID for WAM2\Z24: S-1-5-21-1993962763-2139871995-725345543-1003 </pre> or the username associated with a known SID:<br/> <pre>C:\>psgetsid S-1-5-21-1993962763-2139871995-725345543-1003 PsGetSid v1.43 - Translates SIDs to names and vice versa Copyright (C) 1999-2006 Mark Russinovich Sysinternals - www.sysinternals.com Account for WAM2\S-1-5-21-1993962763-2139871995-725345543-1003: User: WAM2\Z24 </pre> http://www.mycomputingart.com/2008/07/10#Z24.mountimage To get access to the content of a virtual machine image or a ISO file, follow these steps: <ul class="spaced"> <li>associate the file with a loop device node:<br/> <code># losetup /dev/loop0 /var/otheros.img</code></li> <li>list the partition table of the device:<br/> <pre># fdisk -l /dev/loop0 Disk /dev/loop0: 21.4 GB, 21474837504 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/loop0p1 * 1 2609 20956761 7 HPFS/NTFS</pre></li> <li>create device map (<code>kpartx</code> is part of <code>multipath-tools</code> package on Ubuntu):<br/> <pre># kpartx -a /dev/loop0 # ls -l /dev/mapper/ total 0 crw-rw---- 1 root root 10, 62 Jul 6 2008 control brw-rw---- 1 root disk 253, 0 Jul 5 23:18 loop0p1 </pre></li> <li>mount the device partition:<br/> <code># mount /dev/mapper/loop0p1 /mnt</code></li> </ul> http://www.mycomputingart.com/2008/05/04#Z24.audiobroadcast You need to install <a href="http://www.icecast.org/">Icecast</a> and <a href="http://www.winamp.com/">Winamp</a> with the <a href="http://www.shoutcast.com/download/broadcast.phtml">Shoutcast plugin for Winamp</a>.<br> In this howto I explain: <ul> <li><a href="http://www.mycomputingart.com/software/./Z24.audiobroadcast.html#broadcast">how to set up Icecast and Shoutcast plugin to broadcast audio over a LAN or the internet</a></li> <li><a href="http://www.mycomputingart.com/software/./Z24.audiobroadcast.html#delay">how to reduce the audio delay between the server source and the client playback</a></li> <li><a href="http://www.mycomputingart.com/software/./Z24.audiobroadcast.html#rdp">how to use Icecast to replace Skype or MSN voice chat when using RDP</a></li> </ul> <p><a href="http://www.mycomputingart.com/software/Z24.audiobroadcast.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2008/01/20#Z24.mp3catalog This is one of the many ways to keep order amongst audio files and to catalog them. The purpose of cataloging is to have an instrument to always know where a MP3 or OGG file is, if it has been backed up on cd or dvd, how many audio files or hours of music there are on disk, nonetheless to generate playlists by genre or author or by other criteria. <ol> <li>I <i>name the audio files using this schema</i>: <code>Author - Title.mp3</code>. When they are many, a big help come from tools to rename multiple files at once, such as <a href="http://www.ghisler.com/">Total Commander</a> <i>Multiple rename</i> function (Ctrl + M) (Total Commander is shareware)</li> <li>sometimes a <i>MP3 editor to cut and paste pieces of MP3s</i> can be useful, for instance when you bought a remix cd and you want to keep on the disk the single songs, or you want to cut a boring piece at the begin or end of a song (some techno remixes are long and boring at the begin, but great after the first 1 or 2 minutes). A fast and very small editor is <a href="http://www.mpesch3.de">mp3DirectCut</a>.</li> <li><i>correct the ID3 tags</i> of title and author to make them identical to those in the file name: this way all MP3s will be displayed in the same way in MP3 players such as <a href="http://www.winamp.com/">Winamp</a> (for Windows) or <a href="http://www.xmms.org/">XMMS</a> (for Linux) and in the car audio system display (if some MP3s miss the ID3 tags or have them all uppercase or all lowercase). To do that, a useful program is <a href="http://www.id3-tagit.de/">ID3-TagIT</a>: select the files, then select the menu item <i>ID3-Functions, Filename -> Tag ver. 2</i> and type <code>&lt;A&gt; - &lt;T&gt;</code> (artist, hyphen, title) or whatever you like, then <i>ID3-Functions, Filename -> Tag ver. 1</i> and still <code>&lt;A&gt; - &lt;T&gt;</code>; finally <i>File, Save</i> to apply the changes</li> <li>I <i>lower the bitrate to 128 kbps when it's too high</i>, for instance 320 kps. Why? It would occupy too much space while having no hearable advantages (for my ears). The program I use is <a href="http://cdexos.sourceforge.net/">CDex</a>: <i>Convert, Re-encode Compressed Audio Files</i>; the encoding options can be customized in <i>Options, Settings</i> (the encoder, the bitrate, etc.).<br> To see the bitrate of many mp3s at the same time, Windows XP Explorer is very useful: <i>View, Choose Details, Bitrate</i>; the files can be ordered by bitrate, selected and moved in another folder, so that when you have to reencode them with CDex you can select all the files in the "wrong bitrate" folder instead of selecting the "wrong bitrate" files one by one.</li> <li>when some mp3s have a volume that's too high or too low compared with the average, with <a href="http://mp3gain.sourceforge.net/">MP3 Gain</a> the <i>volume can be normalized</i> to the dB specified (I use 89.0 dB): <i>Track Analysis</i> to see the current dB, then <i>Track Gain</i>.</li> <li>organize the audio files in folders as you wish, for instance by genre or author.</li> </ol> Now the audio files are well organized on the disk. Using a spreadsheet it's possible to get statistical data and create playlists: <ol> <li>first I generate a list of mp3s with <a href="http://www.codevisions.de/">MP3 Lister</a>, a tool which can be configured to export all the ID3 tags you want in the order you want, and it can create a txt, csv or html list</li> <li>then I import the text file in a spreadsheet (I wrote a macro to make the import automatic).</li> <li>I wrote other macros to automatically order the MP3 files, check for duplicates and generate playlists by genre.<br> m3u files (Winamp playlists) are simply text files containing a mp3 path and file name on every row.</li> </ol> http://www.mycomputingart.com/2007/12/22#Z24.regexpadv <p>In regular expressions there are some constructs that influence the way a pattern is matched:<br> <ul> <li><a href="http://www.mycomputingart.com/programming/./Z24.regexpadv.html#nongreedy">Non-greedy <code>?</code></a></li> <li><a href="http://www.mycomputingart.com/programming/./Z24.regexpadv.html#noncapturing">Non-capturing <code>(?:pattern)</code></a></li> <li><a href="http://www.mycomputingart.com/programming/./Z24.regexpadv.html#poslookahead">Positive lookahead <code>(?=pattern)</code></a></li> <li><a href="http://www.mycomputingart.com/programming/./Z24.regexpadv.html#neglookahead">Negative lookahead <code>(?!pattern)</code></a></li> <li><a href="http://www.mycomputingart.com/programming/./Z24.regexpadv.html#poslookbehind">Positive lookbehind <code>(?&lt;=pattern)</code></a></li> <li><a href="http://www.mycomputingart.com/programming/./Z24.regexpadv.html#neglookbehind">Negative lookbehind <code>(?&lt;!pattern)</code></a></li> <li><a href="http://www.mycomputingart.com/programming/./Z24.regexpadv.html#regextest">Testing regular expressions</a></li> </ul> <p><a href="http://www.mycomputingart.com/programming/Z24.regexpadv.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/12/22#z24.3ComOfficeConnect <p>This 3Com product has many functions: router, firewall, adsl modem, wireless access point, 4 port switch. 3Com chose to give two names to its products: a name for the market (as the long name in the title), which identifies the purpose of the product and is not changed when a new model replaces the older one, and a model name, a number which identifies the specific model.<br> The "ADSL" term in the name is particularly useful to specify that it's a adsl modem too, with a RJ-11 port that would connect the router directly to the phone line, through a RJ-11 cable, just like any adsl modem; in fact I found several routers that were capable of routing the adsl signal but were equipped with a RJ-45 port instead of a RJ-11 port: they were not DSL modems and needed to be connected to an external DSL modem. Checking the rear of the product, maybe on the user guide, can help making sure the router is a DSL modem too.<br> I will review two 3Com OfficeConnect ADSL Wireless 54 Mbps 11g Firewall Router models, the older <strong>3CRWDR100A-72</strong> and the newer <strong>3CRWDR101A-75</strong>.</p> <ul> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#intro">Introduction</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#pictures">Pictures</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#install">Installation</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#features">Features</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#reliability">Reliability and 3Com assistance</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#wifitrouble">Wireless trouble with 3CRWDR101A-75</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#wifi">Wireless coverage</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#fwrouter">Firewall/router</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#other">Other features</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#missing">Missing features</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#troubleshooting">Troubleshooting</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.3ComOfficeConnect.html#conclusion">Conclusion</a></li> </ul> <p><a href="http://www.mycomputingart.com/hardware/z24.3ComOfficeConnect.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/12/09#z24.AsusMyPalA686 <ul> <li><a href="http://www.mycomputingart.com/hardware/./z24.AsusMyPalA686.html#intro">Introduction</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.AsusMyPalA686.html#package">Package</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.AsusMyPalA686.html#pictures">Pictures</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.AsusMyPalA686.html#gps">GPS accuracy</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.AsusMyPalA686.html#troubleshooting">Troubleshooting</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.AsusMyPalA686.html#conclusion">Conclusion</a></li> </ul> <p><a href="http://www.mycomputingart.com/hardware/z24.AsusMyPalA686.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/12/03#Z24.xen3-winxp-partition Some months ago I made some experiments with Xen and I succeeded to install and run Windows XP as a guest using Xen 3.0. In that case Windows was located in a single file and was installed through Xen. My purpose now is to make Xen running an already installed Windows from its own partition. Just to be more specific, this is my machine configuration: <ul> <li>Ubuntu Dapper Drake 6.06 is located on a SATA disk, set as first boot disk</li> <li>Windows XP is located on a EIDE disk, set as second boot disk</li> <li>Dual boot is made by grub</li> </ul> I want to log into linux and run my existing Windows XP from its own partition on the EIDE disk.<p><a href="http://www.mycomputingart.com/linux/Z24.xen3-winxp-partition.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/11/26#Z24.xen3-ubuntu-amd64 <p>I am coming from a bloody week of wrestling against packages, bugs and "make world"s trying to run Xen in Ubuntu 6.06 amd64 on an AM2 3800+ and to make a Windows XP Pro domU.<br/> I searched on the web some resources that would explain how to run Windows on Xen and I found some very good tutorial that unfortunately don't fit exactly my configuration <i>and</i> my purpose. These are the sites I took as a basis for my setup: <ul> <li><a href="http://www.howtoforge.com/perfect_xen_setup_debian_ubuntu">dom0 = Debian Sarge 3.1, domU = Debian Sarge, Xen 2.0.7 32 bit installed from binaries or source, paravirtualization</a></li> <li><a href="http://en.opensuse.org/Xen_Full_Virtualization_Example">dom0 = SUSE 10.1, domU = Win XP Pro, Xen 3.0.2, Intel VT hardware virtualization</a></li> <li><a href="http://www.howtoforge.com/xen_3.0_ubuntu_dapper_drake">dom0 = Ubuntu 6.06, domU = Ubuntu, Xen 3.0.1 32 bit</a></li> <li><a href="http://www.broermann.com/howto_amd_hvm.html">dom0 = Kubuntu Dapper Drake, domU = Win XP, Xen 3.0.2-2 32 bit, AMD SVM hardware virtualization</a></li> </ul> <br/> These are all the steps I did and the problems I encountered during this Calvary :-) (I come from Windows with a little linux/unix background):<p><a href="http://www.mycomputingart.com/linux/Z24.xen3-ubuntu-amd64.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/10/29#z24.ScytheNinjaPlus <ul> <li><a href="http://www.mycomputingart.com/hardware/./z24.ScytheNinjaPlus.html#intro">Introduction</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.ScytheNinjaPlus.html#pictures">Pictures</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.ScytheNinjaPlus.html#makeflat">Making a flat surface</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.ScytheNinjaPlus.html#install">Installing - ouch, it's not compatible with some MSI K9N Platinum</a></li> </ul> <p><a href="http://www.mycomputingart.com/hardware/z24.ScytheNinjaPlus.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/10/29#z24.Zalman-ZM-MFC1 <ul> <li><a href="http://www.mycomputingart.com/hardware/./z24.Zalman-ZM-MFC1.html#intro">Introduction</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Zalman-ZM-MFC1.html#pictures">Pictures</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Zalman-ZM-MFC1.html#install">Installation</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Zalman-ZM-MFC1.html#pfm">Performance</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Zalman-ZM-MFC1.html#conclusion">Conclusion</a></li> </ul> <p><a href="http://www.mycomputingart.com/hardware/z24.Zalman-ZM-MFC1.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/10/29#z24.Noctua-NH-U12F <ul> <li><a href="http://www.mycomputingart.com/hardware/./z24.Noctua-NH-U12F.html#intro">Introduction</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Noctua-NH-U12F.html#pictures">Pictures</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Noctua-NH-U12F.html#makeflat">Making a flat surface</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Noctua-NH-U12F.html#install">Installing</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Noctua-NH-U12F.html#clearance">Clearance</a></li> <li><a href="http://www.mycomputingart.com/hardware/./z24.Noctua-NH-U12F.html#results">Results</a></li> </ul> <p><a href="http://www.mycomputingart.com/hardware/z24.Noctua-NH-U12F.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/09/21#Z24.controlcmd <p>It is possible to directly open the control panel configuration dialogs writing commands in the Run dialog or in a dos prompt window:<br/><br/> <img src="http://www.mycomputingart.com/images/RunControl.jpg" alt="control command in Run dialog (10k)" style="float:none;padding:1em 0em 1em 0em;"><br/> <code>control admintools</code>: open Administrative Tools<br/> <code>control date/time</code>: open the Date and Time properties<br/> <code>control desktop</code>: open the Display properties<br/> <code>control color</code>: open the Display properties and go to Appearance tab<br/> <code>control folders</code>: open Folder Options<br/> <code>control fonts</code>: open the Fonts properties<br/> <code>control infrared</code>: open the Infrared properties<br/> <code>control keyboard</code>: open the Keyboard properties<br/> <code>control mouse</code>: open the Mouse properties<br/> <code>control netconnections</code>: open Network Connections<br/> <code>control telephony</code>: open Phone and Modem Options<br/> <code>control printers</code>: open the Printers properties<br/> <code>control international</code>: open the Regional Settings<br/> <code>control schedtasks</code>: open the Scheduled tasks<br/> <code>control userpasswords</code>: open the User Accounts properties<br/> <code>control userpasswords2</code>: open the Advanced User Accounts properties<br/> <code>control</code>: open the control panel<br/> </p> <p>If the "Safely Remove Hardware" icon disappears, the <code>control</code> command can help:<br/> <code>control hotplug.dll</code>: open the "Safely Remove Hardware" window </p> <p>Every <code>*.cpl</code> file in the Windows directory can be opened with the <code>control <i>cplfile</i></code> command:<br/> <code>control vp7dec_settings.cpl</code>: open the On2 VP7 Decompressor Settings, if VP7 codec is installed. </p> <p>Moreover, some cpl files accept two arguments:<br/> <code>control <i>cplfile</i>[,[@<i>first</i>][,<i>second</i>]]</code>: the first argument indicates the function (if a cpl file controls multiple functions), the second argument indicates the tab of the window to display.<br/> <code>control main.cpl,@0,2</code>: show the 3rd tab of the mouse properties (main.cpl controls mouse and keyboard, @0 is for mouse properties, 2 is the 3rd tab)<br/> <code>control main.cpl,@1,0</code>: show the 1st tab of the keyboard properties (@1 is for kbd properties, 0 is the 1st tab) </p> http://www.mycomputingart.com/2007/09/15#Z24.remotedesktop Windows Remote Desktop allows to remotely get a Windows session on a Windows XP/2000/2003 machine on which it is enabled from any machine running the RDP client: the RDP client asks the name of the machine and the user and password and then the client opens a window showing the desktop of the server machine.<br/> I'll show: <ul> <li><a href="http://www.mycomputingart.com/windows/./Z24.remotedesktop.html#VNC-RDP-ICA-comparison">Comparison between UltraVNC, Windows Remote Desktop and Citrix ICA connection</a></li> <li><a href="http://www.mycomputingart.com/windows/./Z24.remotedesktop.html#enableRDP">How to enable Windows Remote Desktop in Windows XP SP2</a></li> <li><a href="http://www.mycomputingart.com/windows/./Z24.remotedesktop.html#connectRDP">How to connect to a Windows Remote Desktop from Windows 98</a></li> <li><a href="http://www.mycomputingart.com/windows/./Z24.remotedesktop.html#securingRDP">How to secure RDP</a></li> <li><a href="http://www.mycomputingart.com/windows/./Z24.remotedesktop.html#troubleshooting">Troubleshooting</a></li> </ul> <p><a href="http://www.mycomputingart.com/windows/Z24.remotedesktop.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/06/24#z24.recover-sector-problem A few hours ago while I was using my pc suddenly Windows froze completely (mouse was stuck and Ctrl+Alt+Del did nothing). It's not astonishing but I was quite surprised because such a freeze never happened since I began using Windows XP on my new pc.<br/> The problem appeared at the reboot: <code><a href="http://www.gnu.org/software/grub/">grub</a></code>, the bootloader on /dev/sda, showed this error message:<br/> <p class="error_message">13 : Invalid or unsupported executable format</p> I have a dual boot configuration with Windows XP booting from a EIDE disk and Ubuntu booting from a SATA disk, so I entered Ubuntu, successfully; /dev/hda1 (the Windows partition) was not mounted while /dev/hda5 and /dev/hda6 were; attempting to mount it resulted in <br/> <p class="error_message">Special device /dev/hda1 does not exist</p> At reboot I started Windows XP Recovery Console from the Windows CD and tried <code>CHKDSK.EXE</code>, and this was the outcome:<br/> <p class="error_message">The volume appears to contain one or more unrecoverable problems</p> I booted again linux to launch <code>fsck</code> and see it fail:<br/> <p class="error_message">Logical sector size is zero.</p> <br/> Then I found the solution in <a href="http://ubuntuforums.org/showthread.php?t=179057">ubuntu forum</a>: <pre> root@am2:/home/z24# dd if=/dev/hda1 of=/defmedia/bkup_fat32_hda1.img bs=512 count=2048000 conv=noerror,sync 2048000+0 records in 2048000+0 records out 1048576000 bytes (1.0 GB) copied, 43.61 seconds, 24.0 MB/s root@am2:/home/z24# dd if=/defmedia/bkup_fat32_hda1.img of=/home/z24/sector6.bin bs=512 count=1 skip=6 conv=noerror,sync 1+0 records in 1+0 records out 512 bytes (512 B) copied, 0.011544 seconds, 44.4 kB/s root@am2:/home/z24# dd if=/home/z24/sector6.bin of=/dev/hda1 bs=512 count=1 conv=noerror,sync,notrunc 1+0 records in 1+0 records out 512 bytes (512 B) copied, 0.030644 seconds, 16.7 kB/s </pre> Explanation: <ul> <li>the first dd makes a backup of the first gigabyte of the Windows partition: I copied 1 GB only because I didn't have enough space on a ext2fs to backup all the 28 GB of /dev/hda1.</li> <li>the second dd extracts the sixth sector to a temporary file: as reported by <a href="http://support.microsoft.com/?kbid=247575">Microsoft KB247575</a>, "The backup FAT32 boot sector is located at sector 6 of the logical drive".</li> <li>the third <code>dd</code> copies the extracted sector 6 to sector 0 of /dev/hda1.</li> </ul> In the original post the partition that was just backupped with <code>dd</code> was also checked with <code>losetup</code> and <code>mount</code>. Thanks a lot to the ubuntuforums user Onlymee for his post! <h5>Update 13.09.2008</h5> The same problem happened again today and gave me the opportunity to complete the series of error messages :)<br/> The first, at boot time, was the same: <p class="error_message">grub: 13 : Invalid or unsupported executable format</p> Mounting the partition (<code>mount -t vfat /dev/sda1 /mnt</code>): <p class="error_message">mount: wrong fs type, bad option, bad superblock on /dev/sda1, missing codepage or other error</p> <code>dmesg | grep sda1</code> <p class="error_message">VFS: Can't find a valid FAT filesystem on dev sda1</p> But <code>fdisk -l /dev/sda</code> shows the partition table.<br/> <code>fsck.vfat /dev/sda1</code> (executed from Ubuntu 8.04 alternate cd) <p class="error_message">Cluster size is zero</p> The solution was exactly the same: copy the sixth sector back to the first. And voil&agrave;, it booted. http://www.mycomputingart.com/2007/06/17#z24.mounting-back-fan With the summer approaching, I am making some experiments trying to cool my pc as much as possible while keeping it quiet. Now, airflow in the case is made by 2 fans: the intake fan, a Papst 4412 F/2GLL, pulls air inside the case from the front, the exhaust fan, a Antec Tricool coming with the SLK3000B, pushes air out to the back; in addition, the psu fan pulls air from the top of the motherboard through the psu to the back.<br/> Since I bought a second Papst 4412 F/2GLL, I tried positioning this fan in different locations to see which one conributes the best to the cooling. One of these is the back of the case, in the bottom, where there would be additional cards: it pushes air out of the case through the back slots.<br/> <p><a href="http://www.mycomputingart.com/hardware/z24.mounting-back-fan.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/06/12#z24.hddsuspension The main problem of the Antec SLK3000B case is it converts hard disk vibrations to noise, and this is the most annoying noise coming from my pc when the fans are set at the lowest speed. In the SLK3000B the hard disks lay in a cage with grommets that are supposed to dampen the vibrations of the 7200 and more rpm hard disks.<br/> The trend spreading amongst silencing modders is to suspend the hard disks in the air to avoid contact between the case and the hard disks. <p><a href="http://www.mycomputingart.com/hardware/z24.hddsuspension.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/04/20#Z24.access-registry-out-win Problem: I got myself locked out of my pc<br/> Solution: access the registry from outside Windows and change the account lockout settings<br/> <br/> After <a href="http://www.mycomputingart.com/windows/Z24.remotedesktop.html">enabling Remote Desktop access</a> to access from my notebook to my pc through my wireless LAN, I was playing around with account locking settings to defend from possible brute force attacks coming through the WLAN (supposing the attacker cracked the WPA-PSK password): I set the lock so that after two failed attempts to login the account would be locked until the administrator (me) unlocks it manually.<br/> I wanted to adopt such a security measure for RDP access only, but unfortunately the account lockout policy is valid for any login attempt, being it local or remote.<br/> Then, as a slight security measure, I also disabled the administrator user (my user is already an administrator and an attacker should also find a valid username).<br/> I mistyped the password twice and I got myself stuck: administrator and guest were disabled and my account was locked.<br/> After rebooting, at the logon screen there were no more users, so that the "To begin, click your username" sentence on the left sounded like a joke, having absolutely nothing on the right.<br/> <br/> The solution was obvious: <ol> <li>try to access and change the registry from linux (I have dual boot)</li> <li>manually restore a previous version of the registry</li> </ol> <br/> I solved using <a href="http://home.eunet.no/pnordahl/ntpasswd/bootdisk.html">Offline NTPassword & Registry Editor</a>, an offline regitry editor on a boot disk; I made the floppy, rebooted and then I started looking in the registry the affecting keys, but it was not necessary: there's a feature to edit the accounts, and that allowed me to enable the administrator.<br/> <br/> I also found <a href="http://www.mirkes.de/en/delphi/samples/dumphive.php">dumphive</a>, a useful program to dump the registry hives to text files.<br/> <br/> Instead on <a href="http://www.beginningtoseethelight.org/ntsecurity/">www.beginningtoseethelight.org</a> there's plenty of Windows NT, 2000 and XP low level settings and hacks, I would say "all about the registry": for instance, where and how users and passwords, including account statistics and policies, are stored and encoded in the SAM hive of the registry, and a schematic explanation of the registry structure; and don't miss the other sections of the site, they're enlightening too.<br/> About the second option, there's a <a href="http://support.microsoft.com/kb/307545/">Microsoft article</a> that explains how to manually restore the registry to a previous state.<br/> http://www.mycomputingart.com/2007/03/16#Z24.FileDateChanger <p> <a href="http://www.nirsoft.net/utils/filedatech.html" target="_blank">FileDate Changer</a><br/> <i>License</i>: freeware<br/> <i>Author</i>: NirSoft<br/> <i>Install</i>: no<br/> <i>Size</i>: 50 KBytes<br/> <i>Requirement</i>: Windows 95 or later, comctl32.dll<br/> </p> <p> With this very little tool you can change the Created/Modified/Accessed dates of one or more files at the same time.<p><a href="http://www.mycomputingart.com/software/windows/Z24.FileDateChanger.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/03/16#Z24.Convert <p> <a href="http://joshmadison.net/software/convert/" target="_blank">Convert</a><br/> <i>License</i>: freeware<br/> <i>Author</i>: Josh Madison<br/> <i>Install</i>: no (optional installer available)<br/> <i>Size</i>: 560 KBytes (153 KBytes compressed)<br/> <i>Requirement</i>: Windows 95 or later<br/> </p> <p> Convert is a compact and simple unit conversion program: it converts distance, speed, pressure, temperature, time, volume, angle, area, mass, power, and many more measure units, and it allows to create custom conversions.<p><a href="http://www.mycomputingart.com/software/windows/Z24.Convert.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/03/16#Z24.PanoradoFlyer <p> <a href="http://www.panorado.com/en/index.htm?PanoradoFlyer.htm" target="_blank">Panorado Flyer</a><br/> <i>License</i>: freeware for private use<br/> <i>Author</i>: Karl Maloszek<br/> <i>Install</i>: yes<br/> <i>Size</i>: 250 KBytes (114 KBytes installer)<br/> <i>Requirement</i>: Windows with COM support<br/> </p> <p> Panorado Flyer is a compact program that gathers GPS coordinates from Google Earth and writes them into images EXIF information.<p><a href="http://www.mycomputingart.com/software/windows/Z24.PanoradoFlyer.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/03/16#Z24.CamStudio <p> <a href="http://www.camstudio.org/" target="_blank">CamStudio</a><br/> <i>License</i>: freeware<br/> <i>Author</i>: RenderSoft<br/> <i>Install</i>: yes<br/> <i>Size</i>: 8 MB (1.3 MB install), 33 KB codec<br/> <i>Requirement</i>: Windows 95 or later, comctl32.dll<br/> </p> <p> CamStudio is a free screen and audio recording tool and comes with a swf flash converter and a lossless codec.<p><a href="http://www.mycomputingart.com/software/windows/Z24.CamStudio.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/02/17#Z24.amdcnq I'll try to answer these questions: <ul> <li>What is AMD Cool'n'Quiet?</li> <li>Requirements</li> <li>Does it really work?</li> </ul> <p><a href="http://www.mycomputingart.com/configurations/both/Z24.amdcnq.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2007/02/11#Z24.htaccess Using <a href="http://www.blosxom.com/">bloxsom</a> as my weblog designing application, I had to provide some settings to the Apache <code>.htaccess</code> configuration file to fine-tune the usage of my site:<br/> <ol> <li>tell Apache to load <code>index.cgi</code> in addition to the default <code>index.htm</code></li> <li>rewrite the requested address adding <code>www.</code> if it's omitted</li> <li>rewrite the requested address adding <code>index.cgi</code> if it's omitted</li> </ol><p><a href="http://www.mycomputingart.com/configurations/both/Z24.htaccess.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2006/10/28#Z24.bandwidth Run Group Policy (gpedit.msc) and go to Computer Configuration -> Administrative Templates -> Network -> QoS Packet Scheduler and change "Limit reservable bandwidth" to "Enabled" with a value of 0%. By default it appears disabled but read the description and you'll discovered it's enabled with a value of 20%. http://www.mycomputingart.com/2006/10/21#Z24.mysql Just execute mysqld with the <code>--log[=filename]</code> or <code>-l[=filename]</code> command-line option. If filename is omitted, hostname.log will be created in the mysql data directory.<br> Or edit <code>my.ini</code> adding <code>log=filename</code> line (i.e. if you use WAMP).<br> Then restart mysqld. http://www.mycomputingart.com/2006/10/09#Z24.vmware With this little and very simple tutorial I will explain what I did to: <ul> <li>install VMWare for Windows</li> <li>run Debian virtual appliance</li> <li>connect from Windows host to Linux guest and connect from Linux guest to Windows host</li> <li>run seamless Linux applications in the Windows graphical environment using an X server</li> </ul> <p><a href="http://www.mycomputingart.com/windows/Z24.vmware.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2006/09/16#Z24.ubuntu-on-windows With this little tutorial I will explain what I did to: <ul> <li>install Qemu and its accelerator kqemu</li> <li>create an image file where the guest operating system will be installed</li> <li>install and then run Ubuntu 6.06 Dapper Drake 32 bit as a guest operating system</li> <li>connect from Windows host to Linux guest with qemu <code>redir</code> option</li> <li>connect from Windows host to Linux guest and connect from Linux guest to Windows host using tap driver</li> <li>run <i>seamless</i> Linux applications in the Windows graphical environment using an X server</li> </ul> <p><a href="http://www.mycomputingart.com/windows/Z24.ubuntu-on-windows.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2006/09/10#Z24.wamp-perl I need Perl to run <a href="http://www.blosxom.com/">Blosxom</a>, an open source and free CGI script to create blogs.<br/> So I installed <a href="http://www.wampserver.com/en/download.php">WAMP5 1.6.4a</a> and <a href="http://www.activestate.com/Products/activeperl/">ActivePerl</a> 5.8.8.817 with MSI installer.<br/> I already have my site on my disk, so I told my site directory to WAMP during the setup procedure and then I pointed my browser to http://localhost/index.cgi but it displayed the cgi instead of executing it.<br/> This is what I did to make it work: <p><a href="http://www.mycomputingart.com/configurations/windows/Z24.wamp-perl.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2006/09/10#Z24.blosxom-fixedimages I wrote some post on my new site created with <a href="http://www.blosxom.com/">Blosxom</a> and I wanted to insert some images that I put in a directory called <code>images</code> under my website address root.<br/> I found different solutions:<p><a href="http://www.mycomputingart.com/configurations/both/Z24.blosxom-fixedimages.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2006/08/30#Z24.dualboot-windows-2hd I have a SATA disk and a EIDE disk, I installed Linux on the SATA disk and now I want to install Windows on the EIDE disk.<br/> Because Windows must be installed on the disk that boot first, I entered BIOS and changed the boot order as this:<br/> cdrom<br/> EIDE disk<br/> SATA disk<br/> Then I installed Windows on the EIDE disk.<br/> I want to configure dual boot this way: <ul> <li>default choice: Linux (booting from SATA disk)</li> <li>second choice: Windows (booting from EIDE disk)</li> </ul> I changed BIOS boot order as it was previously (SATA disk before EIDE disk) and booted Linux, then I added these lines to <code>/boot/grub/menu.list</code> (on Ubuntu or Debian; if grub is not installed try apt-get install grub): <pre> title WinXP map (hd0,0) (hd1,0) map (hd1,0) (hd0,0) rootnoverify (hd1,0) chainloader +1 </pre> That means Windows believes the EIDE disk is the first and SATA is the second, so it's happy and if I reboot and choose WinXP from grub menu it starts. http://www.mycomputingart.com/2006/08/27#Z24.wamp-phpcmdline On my old pc I installed Apache, MySQL and PHP singularly, and I made some PHP scripts to be runned from command-line, like this: <pre> c:\php\php -f myscript.php </pre> On my new pc I installed WAMP5 1.6.4, all was running fine (phpMyAdmin, my local website, php scripts pointed to by the browser) but php scripts launched by command-line reported <pre> Fatal error: Call to undefined function mysql_connect() in myscript.php </pre> Obviously I changed the php path to <code>c:\wamp\php\php</code> but with no results.<br/> Solution: change the command to <pre> c:\wamp\php\php -c c:\wamp\apache2\bin -f myscript.php </pre> The -c option tells php to search php.ini in the directory specified, and that's needed because WAMP puts php.ini in Apache bin directory, while with a PHP regular installation php.ini is located in the php.exe directory. http://www.mycomputingart.com/2006/08/27#Z24.pausing-command How to pause / suspend / sleep a running command in a terminal?<br/> Press Ctrl+S<br/> How to resume the paused command?<br/> Press Ctrl+Q http://www.mycomputingart.com/2006/08/27#Z24.script-at-shutdown To dismount <a href="http://www.truecrypt.org/">TrueCrypt</a> volumes at shutdown and reboot time, I created a script, put it in<code>/etc/init.d/</code> and symlinked it into the needed <code>/etc/rc?.d/</code> directories using <code>update-rc.d</code>.<br/> Here is the detail: <p><a href="http://www.mycomputingart.com/linux/Z24.script-at-shutdown.html" class="seemore">See full post ...</a></p> http://www.mycomputingart.com/2006/08/27#Z24.bash-rename Rename all *html files to *test: <pre> for x in `ls *html`; do mv $x `echo $x | sed -e "s/html/test/"`; done </pre> <br/> Bash for: <pre> for <i>var</i> in <i>some-list</i> ; do <i>command</i> ; done </pre> http://www.mycomputingart.com/2006/08/15#about This blog is born in August 2006 and it's about computing science: software reviews, configurations, tutorials, howtoes, for both Windows and Linux, hardware reviews, problems and relative solutions, tips and tricks, and everything else I get through in my computing related life.<br/> The name ComputingArt was born as a "Computing Articles" contraction, but as pointed out by my friend csdk, it reminds to "Computing Art".