So, my cousin calls and asks me to take a look at her computer. He monitor isn't displaying anything, and she has me over to look at it. I bring a new monitor, just in case her old on is fried. It doesn't work, and I checked a few of my old comps to see if they had available AGP cards that fit. None did, and I was going to get one off eBay. The problem is, I don't know if the proper drivers are installed on her comp for the new card I want to install. And if the video card doesn't work, then I can't go online and download them. So I guess my question is, can I put a new video card in, hook a monitor to it, and the monitor work?

She has a Accent Systems PC running XP. The card I took out was a Nvidia Vanta/TNT 2M64 and the one I'm looking to buy is a Nvidia TNT 16 Meg

To install a new vid-card when the old one is on the blink:
install new card, boot up and press F8 a few times. When bootmenu appears, select "Safe Mode" or "Safe Mode with VGA" if that option exists. Go into device manager and uninstall the old drivers, and install the standard VGA (640x480).
Reboot and startup again in Safe Mode.
Install the new drivers that came with the new card. Don't worry if they are not (yet) the latest.
When done, boot in normal mode, rightclick anywhere on your desktop, select Properties, and set the resolution to the one you had before (e.g. 1024x768 or higher), depending on monitor and its screen-size.
If everything works again, look for newer drivers and install those.

You can download those drivers on another PC, then transfer them by email, use a USB-key or burn on a CD.

Don't waste your money on a 16Meg card, look around for e.g. Chaintech MX440, they have 64MB, are 4x or 8x AGP and are dirtcheap new, between $40- $55. Even the 128MB version is only a few dollars more.