I'm getting this issue now every once in awhile, it's super annoying.
I found another forum thread here with a supposed solution, but it's NOT the solution.
I always had done right click 'run as admin' with Windows 7, but I still see this error from time to time. I can put in my credentials and sometimes it keeps asking.
I find it best to have to close the app, then restart it myself.
I'm thinking it might be Symantec Endpoint security once it starts a scan.
Have you checked the SEP logs to see if this is the case? What happens if you start a scan during the day...does it give you the same error?
Normally if an AV is blocking any services you can put through an exclusion, so check this out if this is the case.