Microsoft did well releasing Service Pack 1, but somehow they forgot end users when they introduced a very restricted module of driver signature enforcement. In laymen's terms, all drivers and system files must be digitally verified or they cannot run when using both 32-bit and 64-bit versions of Vista. In the past, it was possible to turn that feature off; but due to new kernel security updates, it is impossible to turn it off without degrading security and stability of your operating system or putting your master boot records in risk by using other software alternatives.