I've closed Remote Administrator and disabled Remote Administrator. I don't know what else could be causing this. Is there a way to find what programs are "using mirror drives"?
I assume this is a Mirror Driver and not a mirror drive. Cause drives wouldn't cause Windows Aero to complain. Now a Mirror driver is a special display driver used in VNC software and the JAWS reader. Mirror drivers, however, are incompatible with Vista/7 DWM.
What have you installed on your PC recently that might fall under the catagories of VNC, display drivers or or JAWS reader? If you need the software, I'm afraid you are out of luck unless there is an updated version of the software. If not, you can uninstall the software and driver. Your call. edit: Here is what finally worked.
We can always give device manager a try. Your mirror driver would be listed under display adapters. Disable it, but leave it installed and see what happens.