Graphic problem!

I have a graphic settings problem.
by default the settings are I am guessing like low. I have a good pc with a gt8500... When I try changing my settings to Ultra High and the other video settings, I hit ok. But they do not get changed. I go ingame and still low, after I hit ok I go back to Display options and it says Ultra high but it really isn't and the other options below that are back to like 0!
Please help I have tried reinstalling but nothing.
by default the settings are I am guessing like low. I have a good pc with a gt8500... When I try changing my settings to Ultra High and the other video settings, I hit ok. But they do not get changed. I go ingame and still low, after I hit ok I go back to Display options and it says Ultra high but it really isn't and the other options below that are back to like 0!
Please help I have tried reinstalling but nothing.