Hi there and welcome
This is 100% a scam. This person was not working for Microsoft and Microsoft would never email you like this.
This is what is known as "email phishing" it is can be a very serious problem if you do perform any instructions they give you. It will normally result in you losing access to your accounts and having fake emails sent in your name.
Basically what they will do is email a lot of people and say that you have problems. Any actual problems you have will be entirely coincidental.
Next they get you to click a link and enter your details into a fake site, then they have your sign in details. This is when you lose access to your account and computer (if you have a later version of windows)
Always remember, no legitimate tech support company would ever email you like this.
Please do me a favor and take a moment to rate my service by clicking the stars above, 3 or more is very appreciated, we can still chat after rating if you need more help.