Hello, Microsoft is on the line…
I find myself telling those who ask my advice for their computers that Microsoft does not make phone calls. No calls to tell the computer user that their system is infected. Microsoft does not have your phone number. They do not track your system day to day.
Microsoft installs Windows Defender along with the operating system software and that software helps to protect you.
If you get a call from anyone telling you Microsoft is on the line, hang up. You will be better for it.