Microsoft won't do it

Last night I had a visitor with her computer running knock on my door. Her computer was telling her, "This is Microsoft. Warning, warning your computer has a virus. Call this number immediately!" She was not sure what to do. She would normally shut her computer down in this situation but this was from Microsoft and that made it different. The truth of it is that does not make it different because Microsoft will never do that. They will not email you or put a pop up on your computer screen. The correct procedure in this situation is to shut your computer down immediately. Most often that means holding down the power button until it shuts down. This is not the best way to shut down your computer ordinarily but these incidents are an emergency. If all is as it should be your computer will be okay when you turn it on again. These scammers cannot get your info unless you click on the message or call that number so never do either one.
As it turns out she was on Facebook when this happened and when we tried to return to Facebook it would not let us in, which told me that is how they had gained access. We tried different browsers on her computer but we were not allowed to sign in to Facebook on any of them. So I had her get on my Chromebook as a guest and she was able to do that and get access to where she could change her password on Facebook. That done she signed into her own computer and was able to get on her Facebook account with her new password.

The last time I had this happen was last summer. After a minute or two of conversation on the phone, I remembered that she had a Chromebook! I said, "Wait a minute here. You do not have a Microsoft computer!" We both got a chuckle out of that one. The scam still could have worked had she called the number.
Change your passwords frequently! I use a password protection program. and this is where you can find it.
Lastpass.com

Another one is Dashlane.com. 

Either of them is secure and safe.