[solved]Can't run Episode One Demo

[Alpha23]

1) Are you really sure you have the latest graphics drivers?
2) Have you managed to start the game and change any settings?
3) Post contents hpl.log found in "My Documents/Penumbra Overture/Episode 1"

to 1) yes, I also reinstalled them
to 2) no, the demo doesn't even start!
to 3) the file is empty!

There are two versions of the Demo - does on of them encounter problems with starting the engine?
Thanks for your support!

Regards, Timo