As mentioned in the cookbook, 16 bit applications are not going to work on 64 bit Vista. This is nothing new: they didn't run on 64 bit XP or 64 bit Windows Server 2003 either. They are still running as usual on 32 bit Vista. There is however one change, Vista no longer gets the icon out of 16 bit executables. You will notice that you get stuck with a generic icon. Not a bug but a deliberate choice.