Go to the Search Charm and type “Change User Account Settings”
Use the slider to adjust the UAC level. There are four UAC levels. The highest will notify you every time a program attempts to make changes to your computer or you change your Windows settings. The second-highest will only notify you when apps attempt to make changes. The third is the same as the second except that your desktop won't dim. The bottom setting won't notify you for anything. Please set the slider to the bottom one in order to turn off UAC.