I spent a couple of hours yesterday allowing a Microsoft person to access my computer, but it was evident they had no more idea than I how to deal with the issue. They finished by telling me my computer was running very slowly (surprise, surprise) and that
it would only cost me a few dollars to subscribe to their technical support. As I feel it's their problem, not mine, I declined.
I first noticed it on my phone, when I discovered I had 4000 of the same single contact. I downloaded an app to get rid of it there, but it came back, so I have disabled Outlook.com and use the phone's own email. However, I don't know how to bulk delete
the contacts from Outlook on the computer - any ideas anyone?