Crashes to black screen

[FLAP_BRBGOING2MOON]

i am consistently crashing to a black screen on my winxp 32 computer. after about 5 mins on the server the screen goes black while the last sound i hear loops, i restart and it every time i join a server the same thing happens. i have tried clearing my cache, turning down all settings to low and turning off m 2nd monitor but as of now ive had no luck fixing this problem

EDIT: got 4 more gigs of ram and win7 problem ceased