I have just been fighting with the Wireless LAN on my desktop PC after a hard restart. Well, I tried everything from adding special entries in the registry to re-installing the device.

My colleagues at work have also been having this problem recently, possibly due to Windows updates. However, what I found was that you just need to go to Control Panel -> Administrative Tools -> Services and scroll down to the option named ‘WLAN Auto Config’ and restart that service and voila, my network adapter can detect wireless networks again.