I recently got a new computer, custom built, and for some reason when I am playing games or watching/playing flash or movies, I will get a No Signal message displayed on my screen and I will have to manually restart, or I will get the blue screen, and I get a window saying my graphics accelerator has shutdown, and that I should restart. Can anyone help me out with this? It has been happening more frequently lately and I dont know why.

do u have a non name brand graphics card?

What graphics card is installed, please? Are the latest drivers for it installed?

Its a Radeon 9800 PRO, and it has its drivers.

I also forgot that I random restarts too.

What have you tried so far to resolve this?

It could be anything, at this point-- a bad video card, or it could even be a bad processor, power supply, or motherboard.

Check power supply first if no name brand power supply are bad replaced if not power supply check Videocard and ram. need spec of whole system then someone will be able to help you better.