Your computer is restarting automatically by design. Most BSOD errors are resolved (at least in the short term) by a simple reboot. We always turn off the automatic restart feature in the computers we build for our customers because it aids in providing support.
First, you need to disable the automatic restart. To do this, you need to get to the start-up menu. This is the same menu you used to get into Safe Mode. If you don't know how to get there, we have written a free instruction article on our website that should help. You can view it at:
http://www.schrockinnovations.com/safemode.php
Once you are at the start-up menu, select disable automatic restart. With that out of the way, let your computer boot and write down the full error for research later if need be.
To test your hard drive, boot from a Windows XP CD. If you don't have a windows XP CD, you can get one from
http://www.bootdisk.com. Once you have booted from CD, press r to enter the recovery console. You may have to press enter a couple of times to get to the c:\windows prompt, but you should get there eventually.
Once there, type in "chkdsk /p" (without the quotes) and press enter. Windows will now perform a quick surface scan of the hard drive. If there are problems, when it is done it will say "Check Disk found one or more errors on the volume." If this is the case, then type "chkdsk /r" (again, without the quotes and press enter. This one could take a while, but it will fix the problems on the hard drive if it can.
Once it is done, then type "chkdsk /p" again and press enter. If it comes back with the same errors on volume message, it is time for a new drive. If it comes back with no error message, then try rebooting. Hopefully, that will resolve the issue.
If it doesn't, you may want to check out the Microsoft website at:
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q297185