wgatray.exe missing

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?

Thank you!

Robert EhingerIT specialistAsked:
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David Johnson, CD, MVPOwnerCommented:
try sfc /scannow to see if it resolves the problem
wgatray.exe is a standard Windows application and it checks if the copy of Windows that is running is a legitimate genuine.  Because of its nature and purpose, it can be considered to be "Spyware" even if it comes with every legitimate copy of Windows.  This is because it's indented purpose it to spy on your computer to see if the copy of Windows you are running is legitimate.  

Many applications that are created to remove spyware from your computer will intentionally remove wgatray.exe for this reason.

You mentioned that there was nothing in the registry referring to wga.

Have you looked here?

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify

If there is an entry called WgaLogon then you may consider deleting it.

More information about wgatray.exe can be found here:
Robert EhingerIT specialistAuthor Commented:
Running sfc /scannow.

I did check HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify and WgaLogon was not there.
Try if a system restore to a date BEFORE he downloaded that program helps

Robert - if the above does not help, a fresh install is often the quickest way out
you can also use the Factory restore partition for this

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