Computer keeps restarting nonstop

[Sky]

I am running on Windows XP Professional. When my computer
was starting up, I accidently pressed DELETE and entered
setup. Once in the setup screen, I needed a password to
continue. I could not leave setup or access the menu
located behind the "Enter your password" box. No password
that I have ever used worked, so I pressed CTRL-ALT-DELETE
to reboot the computer thinking everything would be fine.
That just made things worse. At first it appeared that the
computer was going through its normal paces, but after it
got to the Windows XP screen, and idled there for a while,
the screen went black and then "DPMS (or DPS, I can't
recall which) Mode Off" popped up in a blue box, the
screen went back to black and the whole process began
again. This continues to happen over and over again.
I fear that I have to reinstall Windows XP.
Please help.

 

[Edward]

A suggestion, go back into setup and set to boot from the CD-ROM. Insert the
XP CD and boot. Choose a repair installation.

Good luck,

Ed