I just attempted to install debian over my old ubuntu intallation, but i must have done something wrong. on first boot, it brought me to a login screen, but there was no gui, and a messge popped up telling me that X something failed to start properly.

That wasnt that bad compared to now. Now, the first keypress I make, regardless of whether I press it in grub, debian logon screen, or debian intstall screen from disk, causes a reboot. Is there anything I can do to fix this? I cannt boot to my windows installation on a different installation because i cannot make a different selection in grub, and I cannot reinstall debian beacause pressing enter causes a restart.

Edit: I preformed a fifth restsrt, and now I can boot to tty1, but everytime I try to log in, it says login incorrect. I'm sure that the login is correct. Trying to swich to tty7 results in the same error message as before(x server is not working properly).

Seems you have a hardware problem.

SMPS?
Harddisk?
RAM?

Well, I happened to have the old ubuntu disk lying around, and when I inserted it, my keypresses worked. I decided to install it, and I don't know why or how, but I now have a fully functional version of ubuntu and XP, so I'll leave it at that.