I have looked for an .ini file, with no luck. As to higher demands than Fallout...the issue is developing with an engine you are not comfortable with...Larian did that.
It is the same graphics engine, but uses PhysX and a few other tools to make for realistic visuals...
But, it was not done well.
I have an ATI 5870, I5-750 and 4 gigs of DDR3 1600 and STILL have some areas of slowdown. Wish it worked better, but it doesn't.
If the system is truly Vista (yours says XP/Vista, which looks...weird), then you can right click on the short cut for the game and try the fixes involving turning off these features under Compatibility
Disable Display Scaling
Disable Desktop Composition
And like I said, look at the video cards feature set and see if that helps (make everything application controlled)
Good luck
