Thx, for your answers.
I'm french and english is not my first language.
- i have installed demigod
- i had crash and reboot after 5 mns in game.
- I have decided to install again my OS (winxp)
- then install with impulse demigod again
- when i click on Install, i have this message : "object reference not set to an instance of an object"
I try to phrase things more clearly 
I had .net 2.0 installed, Now I've .net 3.5 SP1, .net 3.0 SP2.
Appeler : Thx, i check it this night and tomorrow
++
S.