[joyel]

I tried every option. Windows screen appears for brief seconds and then computer restarts. This continues over and over again until I turn the PC off. The BIOS screen appears. Haven't recently uploaded or changed software. I have no idea why this is happening. Months preceding this, the computer has shut off unexpectedly, but has always restarted normally.

 

[TheGift73]

Can you post your computer specs as best you can (RAM, GFX card etc), especially what power supply (PSU) you have and the wattage of it. You can find out what power supply you have by turning off the computer and opening it up and finding the label on it.

Also, do you have your Windows XP Disk, or can you borrow one?

Have you also checked that your RAM and cards are properly seated in their slots on the motherboards. Have you recently added any new hardware?

Also, have you tried booting into Safe Mode by tapping F8 when the computer first starts until you get to the Safe Mode screen, and then choose 'Last Know Good Configuration'.

 

[Daifne]

Also in the F8 Safe Mode screen, you want to disable automatic restart. This will allow the machine to show you any BSOD errors. You will have to go into F8 twice. You cannot set both at the same time.

 

[spunk.funk]

Boot off of the XP CD and get to the Recovery Console. Here type chkdsk /R and press enter. The Check Disk utility will try and fix any file errors.