Hello, I have the same problem. The "Geek Squad" checked it 3 times and said nothing was wrong with it. I am far from an expert, but I was able to figure out it was the wireless network adapter. So, what do I do? Can I buy one of these cards just anyplace and install it? I have installed memory and graphics cards before.
Yes, try a different adapter. If your not too far from the wireless router you could get a usb adapter as well. Just make sure the adapter will match the router.
( if you have a a,b,g router don't get a N adapter.)
Before spending money I think I would do the following (obviously you may have tried some already):
See if you can address the router's user interface via wireless (see router manual for details)
See if you can connect to the router (and internet) by ethernet cable.
Check the router's user interface via ethernet and turn off wireless security temporarily -- while in there check wireless mode matches the mode of the wireless adapter. Also look for an option called something like Access List in case it's been set to only admit devices listed by MAC ID. Disable that.
If the above stuff is set wrongly, adding a new wireless adapter won't work.