UAC comes with 4 settings,

The first one stops you doing anything at all that might endanger the OS without typing in a password & confirming you want to do it.

The second isn't quite so aggressive but still locks everything important & requires a password for installing & un-installing. This is the default setting set by Microsoft.

With the third setting you can install & un-install without typing in your password unless you're accessing the important folders (Program files, Windows), this is the one Microsoft suggest for those users who can't stand typing in a password for every single move they make

The fourth setting is OFF, Microsoft doesn't suggest using this one unless you're either very brave, insane or actually know what you're doing, 99% of ordinary Windows users don't. ;)

Windows 7 64Bit
Poser Pro 2010 SR1