User Account Control (UAC) can help you prevent unauthorized changes to your computer. It works by prompting you for permission when a task requires administrative rights, such as installing software or changing settings that affect other users.
We don't recommend turning User Account Control off. If you do turn it off, you should turn it back on as soon as possible.
Open User Accounts by clicking the Start button , clicking Control Panel, clicking User Accounts and Family Safety (or clicking User Accounts, if you are connected to a network domain), and then clicking User Accounts.
Click Turn User Account Control on or off.
If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
Select the Use User Account Control (UAC) to help protect your computer check box to turn on UAC, or clear the check box to turn off UAC, and then click OK.