Windows 7 SErvice Registration disappearing

[mercian777]

Hi

I am repeatedly having the PC lose the service registration. When this happens startup gets almost to the main screen and a black screen appears with a message that windows 7 is an invalid copy.

I have then to run the windows update trouble shooter to have the service registration reinstated.

My cop of Windows 7 is entirely valid so why is this happening repeatedly ?

 

[Trouble]

Have you managed to run the WGA Diagnostic tool successfully?
Maybe give that a go first....
Using Internet Explorer click the following link.
Link Removed