freezing up at login screen-windows 2000

ok i just got a sound card and i went to install it and went through the whole process and what not and it told me installation was complete and to restart my pc so i did and when it booted back up it prompted me for installation again without thinking i x’d out of that and my computer froze up so i tryed restarting and it keeps frezing up at the log in screen….please help.. thanks