Go into task manager, and delete all unknown processes until the icon disappears. The last one you deleted before that is the program that shows that icon. What is it?
Don't stop Explorer. That might cause a shutdown.
An icon has just appeared in my system tray! I have not done anything to have caused this. The icon is a light blue square with something in-determinable inside it. It doesn't show up in a scan of system tray files and doesn't respond to left or right mouse clicks.
How the hell do I get rid of this?