Just received a phone call from these people. Indian accent and reporting that there is something infecting my computer. I already know this is a scam, but play along ultimately revealing that I have a Mac although I really have Windows. This is the easiest test to see if it is a scam or not. When you state that you have a Mac whether you do or don't, they will always immediately hang up on you. Every time!!! If your caller ID defines Unknown Name, or Unknown Name and Unknown Number especially, it is often best just to not answer the phone. If it is a legitimate person attempting to contact you, they will most likely attempt to leave a message on your voice mail if you have it. That's my normal SOP if information is missing on the Caller ID. As M.R. said about these calls, "Very Annoying".

They provide techinical support to  windows operating system

SHILL ---  You are bright little shill aren't you?  Responding to a post from April.  Clear out, you're busted.

Got some info to share on this outfit since they're so worthy of high praise?

Caution - There is a Shill in this thread.  If busted under one name, they have a habit of coming back under other names.

The calls being reported point to an on-going scam.  The scammer will want access to your computer and from there either do nothing and change you for it, or do some data harvesting or leave a bug that they will then charge you to remove.  Microsoft will not call you!  Microsoft is NOT monitoring your computer and they NOT calling you to fix "errors"  Don't talk to these crooks.