About User Account Control in Windows Server 2008

User Account Control in Windows Server 2008 R2 limits which tasks Standard Users can run.

User Account Control divides users into two groups, Standard Users and Administrators:

Standard Users have the least amount of privileges required to perform basic tasks. They cannot install or uninstall applications to or from %SYSTEMROOT%, change system settings, or perform other administrative tasks.
Administrators have full permissions for adding, removing, or modifying programs and user accounts.

By default, users are created as Standard Users. Although User Account Control allows Standard Users to temorarily elevate permissions in order to perform administrative tasks, doing so requires administrative credentials.

For more information regarding User Access Control and the permissions granted to each user type, see the Microsoft documentation at http://technet.microsoft.com/en-us/library/cc731416%28WS.10%29.aspx.

Effects on MDEX Engine Installation

The MDEX Engine installation process has changed with the introduction of User Account Control in Windows Server 2008 R2. Because of the resulting security restrictions on tasks that run at elevated privilege, running a per-machine installation of the MDEX Engine now requires administrator permissions. A user may still install a per-user installation without these permissions, but this is not supported in a production environment.

Note: UAC behavior and installation steps may differ if installing on Windows 7 for development purposes. Consult the Microsoft documentation for details.