That doesn't answer the why, however, which is being asked. Currently, I am mobile so I cannot be detailed. Short answer is Microsoft is to blame here. Driver signing changes were made necessary by Microsoft. Microsoft also ended Vista support. Vista x64 requires driver signing. Vista x86 does not. It is possible to turn off driver signing in the OS but it's a bad idea for security reasons on an already obsolete and end-of-life OS. In short, RedFox isn't trying to hurt people running Vista x64. It's Microsoft that is causing this.