I want to rule out any corruption in the registry or hard disk causing this problem.
Do the following please
Than click Start, type in Wireless Settings and press enter.
Right click on your wireless network and select remove.
Restart the computer
Download CC Cleaner (free) from hereCC Cleaner
(Click Download Latest Version on the top right)
Run it and let it scan and repair your registry.
Once done, restart the computer
Click Start, All Programs, Accessories, right click on Command Prompt and select Run As Administrator.
A black window will open.
Type in it
press enter and when it has completed, type in
It will complain the Volume is in use and to run on restart. Say YES and restart the computer
Connect to the wireless and Let me know the results please