[Osiris]

UAC is the Windows Vista User Account Control. UAC is basically another way to protect the computer from the user, or the user from himself. Much like those ‘Do you really want to delete this file ?’ questions UAC asks the user to give an application additional privileges even if he is currently logged on as the administrator. So, it is basically asking the user the question ‘Do you really want to execute the following application ?’.
Most Windows Vista users get really annoyed after a short while because those UAC popups open many times during a normal session. The only way so far to get rid of UAC was to disable it completely. While this got rid of the UAC popups it did also turn the security feature of completely. Not a big problem for users who know what they can and what they can’t do with their system but surely a problem for inexperienced users.
Tweak UAC is a small software that offers a third possibility. With it you can enable the Quiet Mode for UAC which leaves UAC on for all users but suppresses the UAC popups that pop up rather frequently.

This means that the benefits of UAC such as running programs like Internet Explorer in protected mode will still be available while the annoying UAC popups are removed.
Tweak UAC does not need to be installed on your PC. Just run it and select ‘Leave UAC operating in the Quiet Mode’ when the option appears.
Read More:
Tweak UAC Homepage
via ThinkTechno