GTA4 PC KeyMapping Issues

I want to set myself up some custom keys on the game (instead of wasd i want to use the arrows) and when i do this it unmaps other keys so I remap them aswell. All the keys are mapped to the keyboard like they should be, but when i exit the game says that some keys are unmapped that are necessary. I go through and check, but everysingle key is mapped.

So I exit the key map hitting "accept changes" or what ever it is. I go into the game to start driving the car in the first mission and my phone comes up instead of me driving. I got back to the custom keys and everything defaults on me.

Please help me with this issue.

I bought the game through steam if that makes any diff.