Why wasn't this sent back over the past year?
It could be the OS, Drivers or the hardware. But the USB wifi tells me the OS could be corrupt. Did you restore it to the factory install?
I have a Lenovo G550 laptop with Windoows 7. For the past year it has been periodically (every 5-10 minutes) losing connection with a wireless network. It doesnt matter what network I use , it does the same thing. When the connection is lost it will also cause any other wifi devices (computers, phones) to lose there connection and have to reconnect. I have tried just about anything and everything including using an external usb wifi. Nothing has helped.....If anyone has any suggestions they would be much appreciated. During this thread I have lost the connection twice already