Assuming the wireless is a card and not a chip on the mother board, this method is going to be a little time consuming but it determine if the card is dead.
Shut down the computer.
Unplug it from the wall.
Press and hold down the power button for 10 seconds.
Open case and remove wireless card.
Plug in wall and boot computer.
Let it go through the complete boot process.
Shut down computer.
Pull wall plug.
Press and hold power button for 10 seconds.
Reinstall wireless card.
Plug in wall.
After booting check device manager to determine if the system can see it.
If yes, then use device manager to get updated drivers.
If no then card is dead.
Replace with TP-Link http://www.amazon.com/TP-LINK-TL-WDN.../dp/B007GMPZ0A
Don't use the mini CD that comes with it. Windows will get enough drivers to be able to get on line. Go to the TP-Link website and get the proper drivers for it.