Welcome aboard!
My first suggestion would be to post your complete system specs, it will help the resident gurus a LOT to know what OS/hardware/etc. you are trying to run the game with. Sometimes an issue can be caused by limited system resources, sometimes it's specific to a particular brand of gfx card (and the available tweaks can be different for ATI, nVidia, etc.) so the answers you get will only be as thorough as the info you provide.
