Genuine Microsoft Error - Computer Might Be Counterfeit

It's not really my computer that has the problem. computer has this problem and unfortunately the genuine microsoft error is slowing his computer really badly. His problem is this: It asked for it to do some update on microsoft, so I thought "what the hell, and clicked okay or something, thinking it was the same as windows automatic updates. but after it was done, who would've guessed, It gave him an error saying his computer might be counterfeit or something