Windows Vista x64 originally allowed you to disable enforced driver signing in the bootloader, but this was removed in RC2, and not present in RTM
this meant you have to go into the boot menu ( f8 ) every time you wanted to run an unsigned driver.
a new way has been found to disable driver signing permanently
open up a command prompt (usually start > run > cmd - hit enter)
in the command prompt enter the following
Code:
bcdedit.exe -set loadoptions DDISABLE_INTEGRITY_CHECKS
thanks goes out to Nalin at the XBCD forums for finding this.