Constant errors

I get errors very often but i can't get out of guildwars usually i have to reboot, but it doesn't lock up. But my computer does lock up often my specs are

2.65 gigahertz Intel Pentium 4
8 kilobyte primary memory cache
512 kilobyte secondary memory cache

windows XP Professional (build 2600)

MICRO-STAR INC. MS-6728 100

Board: MICRO-STAR INC. MS-6728 100
Bus Clock: 200 megahertz
BIOS: American Megatrends Inc. V1.5 09/08/2003

RADEON 9800 PRO [Display adapter]
RADEON 9800 PRO - Secondary [Display adapter]
Optiquest V95 [Monitor] (18.3"vis, January 1999)

If thereis more information yuou want i can get it.

NOTE! i hate managed to get 3 errors and copy them so if you can read them message me.

i can't find a reason for it locking up it is all random someone told me my motherboard or processor is fubard