I finally got it to work but it's weird. For some unknown reasons, since I installed DriverStudio, when I start my driver I get a page fault before even entering DriverEntry. I guess that while testing i did something wrong with the registry settings telling windows about my driver or somethign like this.

Anyway as I found this out (blame me I should have tried before to load the driver when softice wasn't loaded and see that there was a problem),
I tried it on a older windows installation I had on vmware and it worked without any problem whatsoever... (using exactly the same steps I described at the top of this thread)

I guess I should try to understand what went wrong with my windows but I'm too lazy

Well anyway, thanks a lot to all of you for helping me !

Regards,