hummmmm i know that it's little "dangerous" ... but if you read all the instructions is easy...
in my case... when i bought my Gigabyte 9800GTX+ it cames with BIOS ver. 2007 or something like that, and i crash always when i go to southeast from MountChilliad, and when GTA:SA try to load too many objets...
but well... visit your VIDCARD BRAND's WEBSITE and find out your MODEL NAME for example:
my model commercial name is:
Gigabyte GeForce 9800GTX+ but my model name inside of brand database is
GV-N98XPZL-1GHyou can search in your vidcard box or manual if you dont know how get the model name...
and read very well the instructions...
This my model...
AND "set" your settings in all lower (drawing distance = null) inside of GTA:SA and set your vidcard on very high quality, cuz it gonna give you a medium loading objets
OR INSTALL WINDOWS 7 ULTIMATE !! HAHAHA MY GTA:SA HASNT NEVER CRASHED IN WIN 7 / but when I switch to win XP... it crash some times (rarely)