There are a few reasons this happens, from the PC being overloaded to changing the display modes. There is a fix that may work , please fallow the steps bellow :
- Go to your Control Panel.
- Open Appearance and Personalization. (Or Appearence and Themes, depending on your Windows version.)
- Click on Display, on the Settings tab click Advanced.
- Next click on the Troubleshoot tab > Change settings , and move the Hardware acceleration slider control until you reach this message : "Disable all DirectDraw and Direct3D accelerations, as well as all cursor and advanced drawing accelerations. Use this setting to correct even severe problems with DirectX accelerated applications."