Error remapping the Action

[Piith]

basicily I had to start from a new hard drive, installed game, updated once first logged on, then play time
well first thing I knew I needed to do was change the keys.

so I do, but there are 3 that I can not, and they are needed very very bad, or I can not use certian weapons or pilot any aircraft.
I can not add keys for Ammo switch or flight Elevate or flight lower and I always get this message when I try to place the key I want fo that action
Error Remapping the Action
now I was wondering if I could just edit something, were I can just change it there, if so where is that I need to get into to be able to change the keymapping???

Thanks