I called the microsoft number and they installed this remotely. Should I now be concerned?

Hello rrob, welcome to the Community!
 
If you called 'the microsoft number' and they did any form of remote session and installed any software, you should be VERY concerned.  There is no charge for Webroot Support with your paid Webroot License.
 
Please submit a Trouble Ticket, ASAP.
 
After you have filed the Trouble Ticket, you may want to take a look at This Thread for more information.

It also appears that this webroot program I have does not have a key code that I can register

@ wrote:
It also appears that this webroot program I have does not have a key code that I can register

That MIGHT complicate things...I am really not sure.  I, like most of the members here, am a volunteer and not a Webroot employee.  We can fix a lot of things without support, but not actual infections.
 
My guess is that "Microsoft" put a TRIAL version of WSA on your computer, which is usually good for 15 days.  The complication is that I am not sure if Support can help you during the trial period or if you must purchase a license first.
 
I think go ahead and submit that Trouble Ticket and let Support advise you as to how to proceed.

I don't believe Microsoft would put a copy of WebRoot on any computer via any of their help lines available. I believe it to be BOGUS. Did you get a telephone call from Microsoft?
In any event I would definitely open a support ticket Support Ticket  and have the situation addressed!