Splinter Cell Double Agent Crash

Well, I know it's common but I've searched gOOgle alot and they say that Splinter Cell DA crashes them only to the desktop >_>
But then in my case after some time of playing the game (The game laods fine) my full PC get's crashed and it restarts again =_=

I've seen a fix of creating a shortcut and putting tha "-ll" but even that doesn't work for me

Also, whenever I try to change the display settings, it reverts back to "next-gen graphics" =_=
I'm not much of a gfx savvy person and all I want is some smooth gameplay

Anybody know a fix to this problem ???

I have a C2D E4600 2.4 GHz
2GB DDR 2 RAM
7300 GT 512mb RAM

I mean Gears Of War works great at 800x600 resolution and everything set to Medium

And darn CRYsis works even more smooth than Splinter Cell DA whith everything except Shadows and Shaders (which are set to low) at medium