Please help! Ubuntu won't start

Since I tried installing RaLink drivers with no success, I haven't been able to reboot Ubuntu Dapper. It just hangs at 'configuring network interfaces' I've tried everything incl Ctrl+C, Ctrl+Alt+F1 to get login. I could login but the window freezes at Window manager. Login at root also froze. I have updated Ubuntu and I don't want to reinstall again, since this has happened before. Is there a way I can repair the installation, or solve this problem? I am currently back at Windows XP.
Please help.

try setting "nomodeset" or ascpi=off from grub menu, google it, cant post links yet :(

sorry didnt notice it was an old thread