OK, here's a link to download TweakUAC for Vista. If the information Brian found is correct, that would be the Vista equivalent of TweakUI. It's a third-party program, but seems to be from a reputable source. You may want to do some targeted searches about TweakUAC and WinAbility Software to be certain about that, but I've found nothing to the contrary.
All this to change an icon! I'm happier with Linux every moment!
Jeff
Email and AIM finally together. You've gotta check out free http://o.aolcdn.com/cdn.webmail.aol.com/mailtour/aol/en-us/index.htm?ncid=AOLAOF00020000000970!