Hmm I'm not sure, every time i open up nLite on Vista the UAC window pops up everytime, i allow the program and thats it. I didn't even have to right click on the nLite.exe and give it Admin privileges. For the people with the problems, are you using the retail version of Vista or the Beta? And although i didn't have to, you can try running the program in windows xp sp2 compatibility mode and see if it works for you then.