If you're using an Nvidia Graphics Card, go to Nvidia Control Panel > Display > Change Resolution and change refresh rate to 75Hz ( You will likely need to do a custom resolution for this). Both Radeon and Intel also has this option though i can't say the exact path to it at the top of my head. Once you have the resolution set in here it should be set like this by default in games, if not check the resolution settings for the game, most tend to had refresh rate included as an option, otherwise just use an FPS counter to see if you're hitting up to your refresh rate with some sort of frame sync enabled so it's locked at your Monitor's refresh rate. Overclocking your Monitor can bring on various issues but without getting to in-depth i...