Left 4 Dead 2 broke a secondary screen and perhaps drivers

Sep 9, 2004
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Now when I try to use my secondary screen which is an old Samsung one, it just says "not optimum mode, optimum mode is..." and then the resolution and hz. Thing is, it is already set to that resolution and the right hz.

Left 4 Dead 2 is like a virus that really seems to **** up computers. Every computer I've ever used to run it, eventually took a big fat clubbing from the game such as broke graphics card, broke drivers, made the computer reboot frequently, bluescreen, etc.

Anyways, anyone know how to fix that bloody "Not optimum mode" screen that is a little box on my secondary screen? It simply won't show the desktop no matter how hard I try.
Jun 20, 2013
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From what I've seen online, the "not optimum mode" means the for some reason the monitor is not set to its optimum resolution or refresh rate. Try using the monitors recommended settings if you haven't done so already.
This problem also may have something to do with your graphics card settings. Some if not most cards give you the option to change the application refresh rate. What card do you have?

Hopefully that helps or sets you in the right direction.