major xp pro -video card problems

[Pouyan]

my windows xp pro was working fine ther was no conflicts
or problems untill my brother started watching xvid
movies on the computer , shortly after my computer would
freeze the grafics would become discoloured and wierd
looking , then the computer would re-boot and restart
with nothing on the screen then restart again try and
dump something and give the message unknown hard error ,
, i fixed this problem by disabling everything under the
sound video and game controller hardware files , and
restarting ,
only a few days later the problem came back but this
time i get blue stripes in the winxp startup screen (the
black one with the logo) horizontally and same thing,
resart dump and i can only start in safe mode , only this
time i cannot fix the problem by just disabling the
sound vid and game controllers , this time the problem
relates to the video card i have downloaded the latest
drivers for xp but this doesnt help and i am suspicios
about the network card as not only does everything work
when i disable my vid cad (of course i cant watch moovies
or anything but at least the computer works) , but i can
get no sound at all, i cant figure this out ,, please
help if you can !!!