Settings problem?

I was seeing what my graphics card could handle yesturday. I selected something that I needed shader support to use. Nothing happened. When I went to start Flight Sim today, it came up with a message saying that I did not have shader support and that FSX would close.
Is there any way to change or reset FSX settings, short of reinstallation, outside of the game itself?
Is there any way to change or reset FSX settings, short of reinstallation, outside of the game itself?