Okay, Now I fixed the freezing by changing some settings to "Use recomended settings" Now when playing the game, the screen flickers, it'll blink white several times, how do I fix it?

Okay, now if you are going to ask me, my video card is ATI Radeon X1300 Series. And my CPU is AMD Athon(tm) 64 X2 Dual Core Processor. 3800 2 CPU's)