I've read that Grub4dos can run from linux using kexec and then I tried to do it with Knoppix 6.2.1 (booted with these parameters : knoppix 2 toram lang=it). Since I want to start the installation of Windows 7 from it,I've saved the Windows installation files on /dev/sda2 = (hd0,1)/winzozz and I've gone into my usb key and I did :

root@Microknoppix:/mnt/sdb1/grub4dos/grub4dos-0.4.4-2009-06-20/kexec -l grub.exe --command-line="chainloader (hd0,1)/winzozz/bootmgr"
kexec -e

it says :

Starting new kernel

and then it freezes for some time and it reboots. Kernel version I'm using is 2.6.32.6 and the grub4dos version which I have tried is 0.4.4-2009-06-20