I keep getting this message when I shut down telling me someone else is using my pc and if I shut down, unsaved work could be lost. But literally no one else uses my computer! I seriously don't get it and I'm usually good with computers but Windows 10 is always giving me weird bugs. I'm even getting paranoid that someone is remotely using it without my knowledge to spy on me. But that's stupid.
Go to; Control Panel / System and Security / System / Allow Remote Access / Remote Assistance / - Make sure "Allow Remote Access" is unchecked.
Probably nothing to be worried about, but if you have the money, you can go to Best Buy and hire the Geek Squad. I've used the Geek Squad Technical Support Service annually for about 3 years (at least). They will inspect your computer, and they'll be able to tell you why it's doing that; sometimes over the phone! bestbuy.com