Dell E2009WFP Monitor - Manual (Page 22)

NOTE: For best user experience and optimum performance of your monitor, keep this feature enabled.
LCD Conditioning This feature will help reduce minor cases of image retention.
If an image appears to be stuck on the monitor, select LCD Conditioning to help eliminate any image retention. Using the LCD Conditioning feature may
take some time. Severe cases of image retention are known as burn-in, the LCD Conditioning feature does not remove burn-in.
NOTE: Use LCD Conditioning only when you experience a problem with image retention.
Below warning message appears once user select “Enable" LCD Conditioning.
NOTE: Press any button on the monitor to terminate LCD Conditioning at any time.
Factory Reset
Reset all OSD settings to the factory preset values.
Exit Menu
Push to exit the OSD main menu.