We need some more details from you. Is the card the PCI version or the AGP version? What make/model is your motherboard? Does it have integrated graphics, or are you replacing some other graphics card (if so, what was the previous card)?
If you had integrated graphics, the usual routine is:
(note: you should already have the drivers downloaded and saved on your hard drive before starting. You can get them from
http://www.nvidia.com/content/drivers/drivers.asp)
1. Boot up in safe mode, and go into your device manager. Find the drivers for your current graphics and delete them.
2. Reboot system into your bios, and see if you need to manually adjust your bios "init display" settings from onboard to "pci" or "agp" (depending on what your card is).
3. Shut down system and unplug.
4. Remove old graphics card if there is one, and install the new.
5. Plug monitor into new card.
6. Boot up into windows, and it should automatically ask you to install the drivers.