BIGG PROBLEM with Windows setup

[fobulous]

So I decided to update to SP2. I pop in the CD and restart computer. I go to BIOS and set dvd drive to run first. Then setup runs. Everything runs normally until I get an error saying "Windows could not load the installer for TapeController." I press ok and ignore that. It also says something about "VIAAGP1.SYS." I got that on a floppy now and continued the setup.
BIG problem though. Setup completed and my computer restarted. POST finished and I barely even see 1/20 of a second of the logo screen before it restarts. It keeps restarting; it doesn't matter if I pick start windows normally or safe mode or whatnot. I of course try to reinstall windows sp2 but the same thing ends up happening. It's basically caught in an eternal loop of restarting.
HELP PLEASEEE.
By the way, I'm a novice with computers

[Dave21]

Try popping in the original XP CD and set the dvd drive to run first and try running a repair to see if that would help.

[Powertrip]

Try changing your shadowing options to disabled in CMOS, or try fail safe option. This may disable things like onboard audio which can cause windows not to start up. I would remove any thing I could like miss matched memory, sound cards, older video cards and see if I could get windows to startup with bare minimum components then add them one by one to see if one is causing trouble.