This method, is in my opinion, the best activation bypass for Windows 7.
First download this utility (RemoveWat). RemoveWat can make Windows 7 looks like an "original" version. Run it and you will see this window:
I tested it on Windows 7 version 7100, as you can see in the below image. However, you can use it and on other versions.
Just select "Remove Wat" and wait. RemoveWat will restart the PC when is done. After the restart, Windows will be activated.
And of course, updates working fine.