Turn UAC off
This option turns UAC off completely. If this is what you want, select this option, press OK, restart the computer, and you wont see the elevation prompts anymore. Windows Vista will operate pretty much like Windows XP does when you login to its administrators account.
Switch UAC to the quiet mode
This option does not turn off UAC; instead, it only makes UAC to operate in the quiet mode. In the quiet mode, UAC does not display the elevation prompts for the administrators. That is, when you attempt to do an administrative task, you will be allowed to proceed automatically, without prompting you to confirm the operation. All other features of UAC would still be enabled: the programs will run with the standard user permissions by default, and the standard users will still see the elevation prompts (the quiet mode applies to the administrator accounts only).
Leave UAC on
If you have previously turned UAC off or switched it to operate in the quiet mode, you can use this option to restore the original behavior of UAC.
Note that if you turn UAC off or swicth it to operate in the вЂњquietвЂќ mode, Vista starts displaying a warning message in its taskbar. You can turn that message off, though: double-click on the shield icon in the taskbar to open Windows Security Center. Then click on the вЂњChange the way Security Center alerts meвЂќ link, in the left panel. Finally, choose one of the вЂњDont notify meвЂќ options.
Note also that if you have used the Local Security Policy tool of Windows Vista to change the advanced configuration options of UAC, they will not be affected by TweakUAC; you would have to use the Local Security Policy tool to modify them.