I have installed a fresh copy of windows server 2008 w SP2 (twice now)and keep having this issue. I have done all the installs and updates as the local admin account setup during the initial configuration. I then join the computer to the domain. I log back in as the local admin and add the server domain security group to the local administrators group. i log in as one of those in the local admin group and attempt to run the Forefront client security install and i get this error "you do not have sufficient privileges to start server setup on this machine. Log on as an administrator, and the restart setup" I get this error logging in as a domain admin or a user in the computers domain security group. i can login as the local admin and start the install but the local admin does not have access to the SQL server where the forefront back end is hosted so i cant do the install. As the users getting the above error i can add and remove server features and rolls so i can only assume that i do have admin rights but for the life of me cant figure out why i cant run the install. I have also tried the "run as administrator" option which gets me into the install but when it trys to call the other install packages it fails... im assuming it doesn't pass the run as administrator parameter to the additional installers that FCS calls during install.

Turn off User Account Control (UAC).Control Panel, Users Accounts, User Accounts (yes twice, its link now middle-top), Change User Account Control settings.

already tried that. I ended up blowing away the whole server and intalling the compennts differently, it was apparently on the collaboration server having issues installing.