Microsoft does not call you about your PC, nor does anyone else legitimate call about cleaning your PC. This is a scam that has been around a long time and people still fall for it. Never let anyone you do not know have access to your PC and never give out any personal information. These criminals use telephone numbers from all over the USA and they manipulate the caller ID. The most recent I see every day is from Brick, NJ. I am an IT professional and network security expert. Don't even be nice - hang up. My business line gets scan calls about 20 times a month.
I was able to keep the caller on the phone for 20-30 minutes by just asking stupid questions. Of course the idea was for me to go to my computer so they could help me remove the "error". I finally said "Do you really have the time for me to unpack my computer from a storage box, then figure out which cord goes where and that I hadn't used this computer in 2 years." He finally hung up on me. Once in awhile I will receive a call from this number but they hang up on me. Guess they realize who they just called. So just try to cut into there sales time by keeping them on the phone. It's actually kind of fun.