Check to make sure the Wifi Card is seated properly - else it could just be screwed.
Check the Device Manager to see what the current state of play is for the device driver... Windows sometimes cannot start a device due to no IRQ's remaining or no address to allocate it too. Used to be a big thing back in the day, but Windows got a lot better at dealing with it, although still not completely flawless.

As for others trying different Wifi cards in Laptops, some BIOS' have whats called 'Whitelists' and will only allow the use of certain cards that are supplied by the manufacturer.
You can get or request for Modded BIOS files to remove the whitelist from them over at BIOSMods or MyDigitalLife's forums.

Info -
http://forums.mydigitallife.info/thr...s-mod-requests