i'm not doing it that way. I downloaded an SP2 ready ntoskrnl.exe, then aplyed modifyPE, and then makecab, then i replaced the original file ntoskrnl.ex_ in I386 dir. By doing this, why does it works on the 1st reboot, and on the next is back to default? And why on the next reboot, windows won't even start? I don't use the boot.ini method, cause i didn't understood it very well, and i think it creates ao opion on boot to select OS, and i don't want that. Thanks for helping.