Window's vista + new wow user interface = no new wow UIFollow

The problem I am having atm. I downloaded the cosmos UI for wow. And when I tried to install it I had no dice. Before I bought my new desktop I had a laptop that ran on windows XP. Now that I have my new PC the operating system is windows vista instead of XP. Im not quite sure how to install a new UI for wow. Thanks in advance for any advice you may have.

Ha Ha... I feel stupid for even asking the question in the first place. Vista is a new program but I still should have been able to figure it out. Thanks for the info. It worked the first time I tried :) Thanks again.