If the following actions were executed, the monitor driver may need to be re-installed.
Change video graphic adapter to another one
Update video driver
Activities on OS, such as service pack or patch
Run Windows Update and updated monitor and/or video driver l Windows was booted with the monitor power off or disconnected.
To find out, please right click My Computer and click on Properties->Hardware-> Device Manager. If you see “Plug and Play Monitor” shows under Monitor, then you need to re-install. Simply remove SmartControl and re-install it.