It's one of those scam calls, "Hi I'm from Windows."  They try and trick you into thinking your PC is being hacked into and that they can help you because they're from Windows and if you follow their instructions, but in reality they're the hackers trying to get into your computer and steal all your info.  Don't fall for it.  They called my house again this morning I answered it and after he said, "Hi I'm from Windows, how are you today?"  I proceeded to scream bloody murder in his ear for awhile and then hung up and blocked the number lmao.