Silkroad wont stop crashing

[Speciest]

Well when I play silkroad I can only play for about 5-10 minutes before my game crashs, sometimes my whole computer restarts,sometime the game just stops and I can go back in, sometimes it crashes the game and I can't click any icons on my desktop so I have to restart.
I have Windows XP Pro
512 MB of ram
120 GIG HD
1.75Ghz AMD Athlon Processor
no sound card onboard sound
ATI X1600Pro Radeon Video card with 512MB memory
I think that is plenty to play I looked at the system requirements and my computer almost has double what I need to play
Does anyone know why it keeps crashing,i can play all the BF games,CS:S,HL2,HL2:DM,Gmod,Delta Force,Guild Wars and more no problem Please Help, Thank You