My Laptop cannot connect to any wireless networks even though it has before. It doesn't list any wireless networks at all, so I can't connect. I've tried turning it on and off, resetting the router, turning wireless connectivity on and off, but to no avail. It was working perfectly fine one minute, and when I turned it off and turned it back on a few hours later, it wouldn't connect. It's a Windows 7 XPS L502X.