For less than 8 bucks I toss some USB WiFi stick on it. I've seen folk reload the OS, change the internal WiFi card but can't tell if you did that yet.
Here's the stick I carry in my bag for such calls.
http://www.amazon.com/USB-Wireless-Adapter-Antenna-54Mbps/dp/B0037G2BMY/
I see there are mini and other versions out there but this one is under 8 bucks to my mail and does not have me driver hunting since Windows 7 stock drivers work.
Beats a repair counter any day.
Bob
I've been having this problem for a few weeks, at first I thought it was the internet itself, but the other computers in the house are fine.
A few times a day it just suddenly stops working and in the bottom right hand corner of the screen in the internet options section it says currently connected to : unidentified network. when I click connect again it says wireless adapter not found, "Wireless Network Connection"doesn't have a vailid IP configuration.
Sometimes it can stay off for a lot longer and it's generally random times of the day that it happens.

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