Desktop Video Card Problems?

I just bought an N-Vidia Geforce 4000 video card for a computer I have built that was running windows xp home and had a 3dfx voodoo 3 card. The manual said to delete the drivers for the current card then take the old out and replace with the new. I did this and now I have no video. Is there anyway that I can fix this problem because the computer seems to start up just fine. The computer over-exceeded the minimum requirements for the new card.