First of all thank you!
I was using the 1.0.0 version of the demo, but with my Win XP SP2 2006 laptop, I was one of those who had terribly slow perfomance turning the game unplayable. I downloaded the 1.0.1 test beta patch (or something like that ) and it solved my problems, the game started to run normally. Therefore, I'm a bit afraid of reinstalling version 1.0.0 I'd rather keep dying and being poor than not being able to play becuase it's too slow