Your best bet would be to create a new GPO to apply to the Vista machines, but be sure to create it ON a Vista machine.
HI,
We r using W2k3 DC's we created some IE based GP in our servers. Its reflecting in W2k machines but in VISTA based systems its not getting applied. What to do for applying IE restriction settings to apply for VISTA machines....
Your best bet would be to create a new GPO to apply to the Vista machines, but be sure to create it ON a Vista machine.