User Account Control (UAC) notifies you before changes are made to your computer that require administrator-level permission. The default UAC setting notifies you when programs try to make changes to your computer, but you can change how often UAC notifies you.

The following table provides a description of the UAC settings and the potential impact of each setting on the security of your computer.

Setting Description Security impact
Setting

Always notify

Description
  • You'll be notified before programs make changes to your computer or to Windows settings that require administrator permissions.

  • When you're notified, your desktop will be dimmed, and you must either approve or deny the request in the UAC dialog box before you can do anything else on your computer. The dimming of your desktop is referred to as the secure desktop because other programs can't run while it's dimmed.

Security impact
  • This is the most secure setting.

  • When you're notified, you should carefully read the contents of each dialog box before allowing changes to be made to your computer.

Setting

Notify me only when programs try to make changes to my computer

Description
  • You'll be notified before programs make changes to your computer that require administrator permissions.

  • You won't be notified if you try to make changes to Windows settings that require administrator permissions.

  • You'll be notified if a program outside of Windows tries to make changes to a Windows setting.

Security impact
  • It's usually safe to allow changes to be made to Windows settings without you being notified. However, certain programs that come with Windows can have commands or data passed to them, and malicious software can take advantage of this by using these programs to install files or change settings on your computer. You should always be careful about which programs you allow to run on your computer.

Setting

Notify me only when programs try to make changes to my computer (do not dim my desktop)

Description
  • You'll be notified before programs make changes to your computer that require administrator permissions.

  • You won't be notified if you try to make changes to Windows settings that require administrator permissions.

  • You'll be notified if a program outside of Windows tries to make changes to a Windows setting.

Security impact
  • This setting is the same as "Notify me only when programs try to make changes to my computer," but you're not notified on the secure desktop.

  • Because the UAC dialog box isn't on the secure desktop with this setting, other programs might be able to interfere with the visual appearance of the dialog box. This is a small security risk if you already have a malicious program running on your computer.

Setting

Never notify

Description
  • You won't be notified before any changes are made to your computer. If you're logged on as an administrator, programs can make changes to your computer without you knowing about it.

  • If you're logged on as a standard user, any changes that require the permissions of an administrator will automatically be denied.

  • If you select this setting, you'll need to restart the computer to complete the process of turning off UAC. Once UAC is off, people that log on as administrator will always have the permissions of an administrator.

Security impact
  • This is the least secure setting. When you set UAC to never notify, you open up your computer to potential security risks.

  • If you set UAC to never notify, you should be careful about which programs you run, because they'll have the same access to the computer as you do. This includes reading and making changes to protected system areas, your personal data, saved files, and anything else stored on the computer. Programs will also be able to communicate and transfer information to and from anything your computer connects with, including the Internet.

  • Open User Account Control Settings by clicking the Start button Picture of the Start button, and then clicking Control Panel. In the search box, type uac, and then click Change User Account Control settings.

Note

  • If you're using an accessibility device, such as a screen reader, we recommend that you choose either the Always notify or the Default - Notify me only when programs try to make changes to my computer UAC setting. Assistive technologies work best with these two settings.