I think this all started when somthing from the internet was installed that was supposed to update our video player. Then we had some kind of virus or company saying that we have to buy one of their products to have it removed from the computer. We couldn't get on the web and surf without it defaulting on this certain page of this company. We finally found someone that could remove the default problem and the prompt for us to buy their products. Since then the computer stops or freezes when surfing the web or when video is being played and then the screen goes black. I have to move the mouse to get it to go back to the web page. The videos continue running but the image stays the same then goes black and thats when I have to move the mouse to get it to return. My video card is only about a year old, and I have not had any problems with it overheating. When I try to play a video game now all it I somtimes cant even see anything on the screen or I see stuff put the light burst scatter all over the screen and then it will go back to normal, but most of time it's not visible. When I try to move the mouse when video games are on the screen freezes worst than on the web and It somtimes doesn't even unfreeze when I move the mouse. Someone out there will earn the computer tech master if they solve my problem.