It's a more common issue than you'd think. My parents computer had a similiar issue. The problem lay with one of those regular Windows updates your computer regularly makes you download being faulty(sorry can't be more technical) and it thinks your copy of Microsoft isn't genuine. On my folks computer, on all four corners of the Desktop it'd say "Your copy if Windows may not be genuine", after a bit of Googling I found the update at fault, uninstalled it and Windows went back to normal(still recieve regular updates no problem). That program is grand, and will hopefully solve your problem. It's definitely not any scam/spyware type thing. Download it and see what happens.
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