On my Vista OS computer,  Poser 8's default is to load its Poser Content to Desktop/Public/Pubilc Documents/Poser 8 Contents.  You will want to know this if you are going to change figure textures etc.  You can turn UAC off, however I certainly agree with Hioushi--better off not to. 

If you REALLY want to, click on Windows  MS Logo, then Control Panel, then User Accounts, turn User Account Control on or off.  When you disable UAC, Windows will immediately notify you that it has happen and will continue to bug you until you turn it back on. Jan