I thought I might try asking here since I couldn't find a solution to my problem anywhere, or maybe I didn't search correctly, but I just don't know how to describe this:
Basically, I get a box with a gray background after right-clicking any icon in the taskbar. However, right-clicking icons in the notification area works correctly.
Screenshot of the problem:
This happened today after doing a clean install of Windows 8.1 Pro, installing drivers, and getting Windows updates, nothing else.