MusicFret, do you have any CD's that came with your computer? In a pinch like that I've had to go back to the manufacture's disk and re-install the drivers.
I'm going to throw up a guess that your PCI Bus driver is missing. Probably due to Windows being reinstalled, or by some accident in Device Manager. If that's the case, adding a wireless card behind a non-working PCI Bus is not going to help you. You probably need to find out who makes this computer and get the "chipset" driver from them and install it. Once that's cleared up, you'll need to install the network drivers. After that, you should be back on the Internet without much more hassle and you can get the rest of the drivers off the internet.
What computer did you use to post the message? Can it be used to download the drivers and save the files onto a flash drive?
Just curious, what were the circumstances between the computer working and not working?