Google the name of the wireless card and check for driver downloads from the site of the people who make it. You might find that the drivers are newer than the ones you've got on the PC. Even if they're not, once you've downloaded them, tuck 'em away in a folder somewhere, then remove the software.
Restart the PC, and right-click "My Computer", click "Manage", double click "Device Manager" and you should be able to see the wireless card in "Network Adapters". If it looks ok, then you're good to go. If it's yellow and question-marked, you've probably removed the drivers. In this case, you can double-click the wireless icon, and follow the "troubleshoot" option. At some point you'll be asked if it can search for drivers, and you should direct it to the folder where you've stuck them. That should work.
Andy