My understanding is the Windows 7will let up up date things except Windows 7 itself. Their is also a chance that a infection changed Windows files causing this to happen. Three things I recommend for check above and beyond your anti virus scans.
Malwarebytes Anti Malware
Eset on line scan
Windows defender off line. Malwarebytes
---------- Free Online Virus Scanner | ESET
Windows Defender Offline
Up date all of them and then run Full scans with each, one at a time.
The reason is no one program finds everything.
I noticed that about a week ago Noel recommend you to post a MGADiag in the activation forum. After you are sure you are not infected that is what you should. Windows Updates & Activation - Windows 7 Forums