Is there any more of the message such as "Unmountable boot volume"
Power off
Desktop:...Open the case and reseat the hard drive IDE ribbon cable at
both ends.
Laptop:... simply remove and reinsert the hard drive.
If that fails:
http://support.microsoft.com/?kbid=297185
http://support.microsoft.com/?kbid=315403
Otherwise go to the website of the hard drive manufacturer and
download their hard drive diagnostics.
Do you have a hard drive overlay such as Max Blast?
Windows XP sometimes has issues with overlay software.
You may need to perform a Clean Installation without their overlay
software which is not needed anyway.
