I have a client with a business computer running Windows 7 Pro that came installed on his computer. He has had this PC for about 3 year with no problems. Last week he downloaded a program and the problems began. He got infected by malware and some trojans. Once we got that cleaned up everything seemed fine for a few days and then he started getting messages that his copy of Windows isn't genuine and his background turned black. This installation of the operating system came with his computer. I check the activation status and it shows that windows is active and genuine. In the course of trying to repair this problem I discovered that there is no instance of wgatray.exe and there is noting in the registry either referring to wga either. How do I fix this problem?