The default location of Windows memory dump files in Windows XP is %systemroot%/minidump , where %systemroot% is your Windows installation directory. In most cases the dump files are located in C:\Windows\minidump folder. These dump files are created as a result of a blue screen, which may occur due to bad drivers or faulty hardware. These dump files can be read using Windows DumpChk.exe utility or from Debugging tools for WIndows and Windbg utility. The following articles from Microsoft explain how to use these tools to check for the offending driver or hardware that is causing the blue screen:

http://support.microsoft.com/kb/315263

http://support.microsoft.com/kb/315271/

http://www.microsoft.com/whdc/devtools/debugging/default.mspx