Display

I was adjusting the display hardware on my new PC CPU I7 OS win 7 pro. 64byte.
I have made a mistake and now I can not get it back.In the Hardware window I have lost it all except the target frame rate, nothing else works. only 4 colours and no 3D etc just looks horrible.
Q. DoI have to change something in the display CFG file? If so what?
I have tried uninstalling and reloading several times but it makes no difference.
FS9 in WinXP Pro creates another file in documents and settings but I can not find it in Win 7 Pro. PLEASE HELP.
Problem number two.
I purchased a logitech Extreme 3D Pro joystick but on my old PC Win XP Pro I keep getting the Blue Screen of death. I have downloaded a lot of update driver files etc. but it is still doing it. I installed it with the disk and followed the instructions. but no go.
This is the first time I have ever asked for HELP and I know I am not the sharpest knife in the block. Thankyou brucie of New Zealand. Earthquake territory. [/b]