Typical Windows 7/8 problem. This has happened a lot. There are a few things you can try involving your wireless driver and control panel options.
1) in control panel > device manager find your wireless driver, right-click it and uncheck the box that says "allow windows to turn off this device to save power"
2) in power options choose your wireless driver and set it to full power
I used to know them all but forgot all the ways.