Ok it works.
Only DVDs can boot in EFI mode. USB Sticks are bootable but not in EFI mode and the result is that the wrong bootmanager is loaded.
Does Intel plan in the near future to support USB boot in EFI mode?
can you share how you make it work?
Well, you need to use the installation DVD of Windows 7, and not a USB Key.
It seems as the motherboard doesn't support USB boot in "UEFI Boot" mode, well it boots but the wrong boot manager (the standart one and not the efi boot manager).