calls and says there Microsoft windows ,and that they have a report of popups from your computer.then trys to get you to do a few steps to give them access to your system.If you hangup they will call you back.# comes up unknown.i told them i needed a call back # so i could get my comp started ,he argued with me then gave it to me.i hung up and they called several more times,i did not pickup.i called Microsoft and that # is not registered in the Microsoft system and was told they are scammers/fraudsters trying to get your info from your comp.i called the # back and confronted the man with this info and wow he got mad that i would have dun this and then called him to tell him and they hung up on me ,lol