Hi Carl,
I am Sumit, an Independent Advisor and a 2-Year Windows Insider MVP here to help.
Via Bruce Hagen's post from here:
https://answers.microsoft.com/en-us/protect/for...
It's a scam.
Use the Task Manager to exit the browser. Reboot and see if the pop-up goes away.
How to Use the New Task Manager in Windows 8 or 10
http://www.howtogeek.com/108742/how-to-use-the-...
How to Use the Task Manager in Windows 7
http://windows.microsoft.com/en-us/windows/end-...
If that does not resolve the issue, follow the instructions here.
For Edge:
User Scott_Ki has provided this solution.
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When this happened to me, I closed Microsoft Edge using the Task Manager.
Then in the search bar next to the Windows 10 logo on the bottom off the screen (I call it the "Cortana Search"), I typed in google.com and hit enter.
Microsoft Edge opened up with a new tab for Google. You can see the offending site still opens in a tab that doesn't have focus. Click the "X" to close Edge. Do not click on the offending site tab or it will get focus again.
When Edge closes nicely, it won't "Restore" the sessions and the offending site tab will be gone.
Source:
http://answers.microsoft.com/en-us/protect/foru...
And if the problem persists:
Remove Tech Support Scam pop-up (Call For Support Scam)
http://malwaretips.com/blogs/remove-tech-suppor...
Disclaimer:
There are links to non-Microsoft websites which would provide accurate and safe information. Watch out for ads on the websites which are frequently classified as a PUP (Potentially Unwanted Products). There is no need to buy paid products to fix your computers as they do more harm than good sometimes.