Windows 7 optimal resolution notification

Sounds like an annoying UAC pop-up you might try changing your settings via Action Center

Once you've set your resolution in Windows, this should not come back. Are you sure it isn't a notification from your monitor? If you've set your resolution to other than the monitor's native resolution, your monitor may be advising you of it. Do you see a message similar to "Press 1 to clear, 2 to disable this message?" If so, this is a reference to the #1 and #2 buttons on your monitor, not your keyboard.