tried installing my video card, but screen just stays blank after WIndows XP logo screen

I found a lot of previous posts describing this problem, but no
solutions. Just bought myself a new video card, and plugged it into
the AGP slot on my computer (i'd never done this before on my own),
and when I start it up, the colorful WIndows XP logo screen appears
fine with the little scrolling progress bar at the bottom, but then
the whole screen goes blank, and even though I can hear the CPU
processor continuing to "work" as though windows is booting up, I
can't see anything; the screen just stays dark.

I uninstalled my existing video card drivers before installing the new
card, like I was told...this problem sound familiar to anyone? Any
suggestions? Please POST, do not email replies.