It sounds like a driver update might fix your problem. To update your drivers, simply go to your graphics card manufacturer's website and download the latest drivers for your card. If you don't know what card you have, you can download a program like Speccy
. Once installed and run, it should tell you the specs of all the hardware inside your computer.
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Also, make sure that you're setting the resolution of the game to the correct aspect ratio. (i.e. 16:9, 16:10, 4:3) This is done through the resolution settings. If you're not certain what your aspect ratio is, there's an easy way to make sure that you're using the correct one. Simply take your native resolution and divide the first number by the second. The result will be something like 1.6. This simply means that the first number width should be 1.6 times the height [16:10]. When choosing your resolution in game, either choose your native resolution or make sure that width divided by height gives your the same result as your native resolution.
My native resolution is 1680x1050. This uses an aspect ratio of 16:10, or 1.6:1.
When choosing a resolution I need to choose one that results in 1.6 when I divide width by height. 1440 x 900 or 1280 x 800.