My windows has suddenly stopped being genuine?

[Based Otakkun]

Okay so about a week or so ago, when I booted up my computer, I got a message saying "You're copy of windows is not genuine". So now the back of my desktop is black and says "Windows is not genuine". So then I downloaded the update from microsoft. Now so when I try to enter my key I get the error

"0xC004F074
The Software Protection Service reported that the computer could not be activated. No Key Management Service (KMS) could be contacted. Please see the Application Event Log for additional information."

So I ran my AVS and found quite a few threats and removed them. But still I get that error.

Microsoft's solution says to Troubleshoot errors from each event ID 12288 associated with the activation attempt.

But I have no idea how to do that.

Can someone help?

 

[Dark Lord of Tech]

http://windows.microsoft.com/en-US/windows7/activate-windows-7-on-this-computer