When someone calls out of the blue claiming to be a Windows expert who has detected Error messages on
your computer and is willing to fix them for you - at a hefty price, of course - it is an international SCAM.
Started from India, according to this article, many shops are set up here in the US, Australia, UK, Europe, etc.
They know how to disappear immediately so they can not be traced by angry "customers" taken in by their
scare tactics.
Read the article here to gain all the specifics of the tricks they play.
Just be sure to never let anyone have Remote Access to your computer, unless, I would guess, it is from
an antivirus program provider that you have paid for legitimately.
I never heard a single word about the scam style detailed in the clearly-written warning article below.
But we all need to know. These people are not harmless cranks; they actually are so vindictive that once allowed
Remote Access by your own permission, and you don't agree to pay them the money they want, they will tear up your computer !
They sabotage files and your internet connection and may even totally destroy it. This shocking revenge was
detailed in another article on the same blog run by experts fighting mallware.