First, these pop-ups are nothing but a web browser hijack that is easily cleared simply by using Task Manager to close the browser then restarting the browser and clearing the cache and history.
Second, all calls claiming to be from "Windows" or "Microsoft" claiming they are getting messages from your computer are scams.
Third, the scammers are operating from a foreign country meaning it is very difficult for our government to do anything to shut them down although some success has been had with those running the fake IRS agent scam.
They call stating because you are not a criminal and because of your tax status you qualify for a $9000 grant. They ask for bank account info or state they can transfer money western union but are given another number to speak to someone regarding the transfer of funds. I researched before calling and found this is a scam. They ask you to send $250 or place it on some type of card before they send the $9000. This is a scam.
They called me today. I got smart with them and said a few choice words. They called me back and called me a a$$hole.. I hung up then they called back again cussing. I blocked the number.