"Microsoft did well bringing the 64-bit architecture to Windows Vista but somehow they screwed up. Apparently they forgot who their target audience was 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 the 64-bit version 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.

In order to turn this off it involves uninstalling critical security updates that Microsoft has released to increase system security. Sadly, this feature makes Windows Vista 64-bit into a closed and locked down operation system.

So what's the problem with digital certificates? Well, the problem is. developers have to pay Microsoft to receive verified certificates, and that makes many applications inaccessible under Windows Vista 64-bit. This driver signature enforcement can be a serious pain to end-users; however it is still possible to turn it off by disabling it up by pressing the F8 function key during system boot up.

Pressing F8 every time on boot up can be a serious pain in the ass and frustrating to those that miss the time window available to press F8 during start up. Others have found workarounds, but most of them are too complicated for the average end user to perform, atleast until now."