Symptom: After exiting the system, a blank window remains on the screen.  This is after the system asked if a backup was desired.
Cause: Some hardware does not honor the close window command after the application closes.
Remedy: So long as the application has asked if a backup was desired, then it is safe to close the window using the Windows close button (this is the X in the upper right of the window).  The application has already ended and after closing this window it is safe to SHUT DOWN the computer.
HOW TO FIX IT:
No fix!  This a hardware specific but will not hurt anything so long as it is closed after being asked if a backup was desired.