Run chkdsk /r and then run sfc /scannow...or do a repair install. Alternatives will ensure initial integrity of system files.
How To Run CHKDSK In XP - http://support.microsoft.com/default.aspx?...b;en-us;Q315265
LEARN how to use SFC.EXE (system file checker) in this article! - http://www.updatexp.com/scannow-sfc.html
Perform a Repair Installation - http://www.microsoft.com/windowsxp/using/h...ips/doug92.mspx
Look for errors about your system in Event Viewer. Double-click on any error for details. Post details here for last 4/5 errors noted.
Check Device Manager to see if all drivers are installed.
Run chkdsk /r on the hard drive.
I guess I don't see where a BIOS update would help, since there is no indication of hardware incompatibility or added functionality that a BIOS update would settle.