1. your eyes are closed.
2. the machine is really not running. you are simply "hearing things"
3. the game you are trying to play is so bad that your PC's inbuilt Cr@p filter will not display it
4. Your laptop took an arrow to the knee.
Now seriously, You may consider your system credentials Not Applicable but in these forums you will get better responses to your questions by providing a detailed description of your system including make/model and as well as the operating system you are working with. Answers applicable to WinXP may not work for vista or Win7. You have also not outlined which games you are having difficulty with. It may simply be a case of your system not being up to minimum requirements for the game you are trying to run. We can presume you have normal graphic display doing other things on the machine so it is unlikely you have a hardware issue.
Goin' Fishin' (Some day)