graphics problem
 

hi all

i am new in this forum and this is my first post. i need help.i have problem with my computer when i play a any type of game and during the game automaticaly screen is black and some time freez.and then i restart the computer and evry think is normal.but i face the problem only when i play the game.

p4
3.0
asus
sis chipset
ati 9250 graphics card
512 ram

any type of sugestion will accepted.

thanks