Windows Vista has the built-in ability to automatically reduce the potential of security breeches in the system. It does that by automatically enabling a feature called User Account Control (or UAC for short). The UAC forces users that are part of the local administrators group to run like they were regular users with no administrative privileges.
Now you need to start msconfig utility from
Click on the Tools tab. Scroll down till you find “Disable UAC”. Click on that Press the Launch button.
A command window will open. When the command is done, you can close the window.
Close MSCONFIG. Now you need to reboot the computer for changes to apply.