The graphics setting cannot be changed!

Ganger]

I got the game recently from my friend and it works fine for him!
Now i can't change my graphics setting like
800x600
full screen
high
high
blood off
gamma 0

I want them 180 degrees!
and the sound settings are all off and 0

And i can't play the game on full screen like there is a black sides taking half of my screen from both sides

I can't save my id in the login screen (i can save but when i login again i don't find it! and the save my id isn't checked)

any help?