Windows 7 may occasionally display a symptom where the screen flashes after user optimizes the computer shutdown speed. The symptom happens whenever user selects a folder or browses to new web page, the desktop which supposed to be in the background will jump or bring to front – flash out for a while, and the “Not Responding” error message will display on the top left corner.

The problem is probably due to optimization to increase PC shutdown speed and decrease time required to shut down the computer. The change can be used by Windows optimization utility or technical user who modifies the registry manually. When the setting is changed, Windows 7 may encounter lack of buffer time or other slowness.

To fix the screen flashing issue, follow steps below.

Run Registry Editor, and then delete the following registry keys:

HKEY_USERS\.DEFAULT\Control Panel\Desktop\HungAppTimeOut
HKEY_USERS\.DEFAULT\Control Panel\Desktop\WaitToKillAppTimeOut
HKEY_CURRENT_USER\Control Panel\Desktop\HungAppTimeOut
HKEY_CURRENT_USER\Control Panel\Desktop\WaitToKillAppTimeOut
HKEY_CURRENT_USER\Control Panel\Desktop\WaitToKillServiceTimeOut

Restart the computer after deletion, and the screen flashing issue on Windows 7 should be fixed.