Well, obviously you have installed a cracked version of windows7.
But that's not the problem, the problem is you most likely have either auto-update configured where you are not prompted to install updates and it runs in the background. Or you manually installed all the updates recently. The specific update that verifies and patches cracked Windows7 is
kb971033. So for future references, for you or anyones else, if you have a cracked Windows7 installed (regardless whatever the cracked version .info file say about it being immune to Genuine Advantage Check), make sure you don't have it configured to auto-update. Just manually update once a month and check individually to see if any of those updates are WGA updates and don't install them. Windows doesn't bundle these updates so there are separate from all other updates and easy to single out and ignore.
Now that you know why it happened and how to prevent it in the future, time to fix it.
You can try
this method or use your
google-fu.