I'm new to this forum but have browsed a lot in the past. I want to share how I fixed a problem on my husband's laptop with the rpcss dll. I downloaded Norton Power Eraser (free) and ran the scan. The scan found an issue with rpcss.dll. I ran the fix option and since rebooting, the problems went away. Prior to this, the laptop would pop up with odd security messages and also prompted to start Windows Security Services (Windows 7). After running Spybot scans and Symantec scans, it still didn't resolve the issue. So I resorted to the Power Eraser.
Hope this helps those having similar problems! Good luck!