Issue
In Vista Workstation 4.20 or 4.21, when using full screen mode (F11), if all windows are closed, a gray screen is displayed.
Environment
Vista Workstation 4.2.0 or 4.2.1
Cause
Closing all windows results in an empty display, but it is still taking up the whole screen.
Resolution
The only way to exit full screen mode is to use the ESC key.