Hi there and welcome
This is 100% a scam, and it is a common trick they use. There is no infection detected by this message.
Did you call the number? Or have any contact with them?
As requested, I have offered it and once accepted will call you and check out your computer.
That is no problem, you requested it so I offered, but we continue here
I need to know please
Ok, then there is the chance he installed a virus or something else.
Can I connect to your computer (I'll do it at no extra charge) and check this please?
Can you go to www.teamviewer.com
Click on Download in the middle of the page
Download and install the program and give me the ID and Password ***** please so I can connect
Do not close the program but leave it open else I will not be able to connect