VISTA / Windows 7 - UAC - What is it and should it be enabled or disabled?(SI009)
A feature of Windows VISTA / Windows 7 is UAC or User Account Control. This is a mechanism through which the operating system protects itself, through user challenge and intervention, regarding system critical files and functions.
For more detailed information on this you can read the extensive articles at the Microsoft TechNet site.
In general, and specifically for SSP use, the disabling of UAC will give a more "XP like" user experience with respect to file interaction. While this may resolve some issues in SSP and prevent the UAC dialogs from coming up, we do not recommend globally disabling the UAC feature in Windows Vista. If you choose to do so, we recommend fully reading the information found at the Microsoft TechNet site to understand the system-wide ramifications of this change.
There are, however, other specific ways to allow user intervention and file execution that we may address from time to time such as running a particular executable as an administrator, or running programs in compatibility mode for Windows XP (Service Pack 3). Look for specific KB articles addressing these situations.