Something is clearly causing corruption to the registry, try the following
to see if you can source the cause. NOTE: I understand you've turned off
error reporting, if this means no errors appear in the log mentioned below,
turn it back on and run the system a bit as you normally would including
your bootup in order to ensure any such potential causes are recorded in the
Event Viewer as described below:
First, be sure your antivirus software has the latest definitions and run a
virus scan.
Also, download, install and run Ad Aware:
www.lavasoftusa.com
If your system is clear of viruses and any malware, open Control Panel, open
System, go to
the Advanced tab, click Settings under Startup and Recovery, remove the
check from "Automatically Restart" under System Failure. This will cause
the system to blue screen instead of restarting on errors and the
information on the blue screen may give a clue as to the source of the
issue.
Open Control Panel, open Administrative Tools, open Event Viewer, look for
errors corresponding to the crash, double click the error, the information
contained within may give a clue as to the
source of the problem.
Assuming you have an XP CD and not a recovery CD, place the XP CD in the
drive, when the setup screen appears, select "Check System Compatibility,"
the report it generates may point to problem hardware or software on your
system. If you do not have an XP CD, you can download this application
known as the Upgrade Advisor from the following site:
http://www.microsoft.com/windowsxp/pro/howtobuy/upgrading/advisor.asp
Note: If you have access to a broadband connection it might be best to
download using that as this is a rather large download.
Check for the latest drivers for your hardware, especially your graphics
card and soundcard and all peripherals connected to your system. No not use
Windows Update for this, go to the device manufacturer's web sites and if
you install updated drivers, ignore the message about drivers being unsigned
by Microsoft.
