Half-Life 2 Crashes

[Rakabicyk]

Bought and installed Half-Life 2 like any other games from steam but this one seems to have some kind of problem. Its crashes very often, like 3 or 4 times in half an hour, and other times its perfectly fine and i can play for hours. Wen it crashes the game freezes and i have to press control alt delete to reset the game. Any idea of what is causing that, anyone?