User Account Control (UAC) is a feature in Windows that can help you stay in control of your computer by informing you when a program makes a change that requires administrator-level permission. UAC works by adjusting the permission level of your user account. If you’re doing tasks that can be done as a standard user, such as reading e‑mail, listening to music, or creating documents, you have the permissions of a standard user—even if you’re logged on as an administrator.
When changes are going to be made to your computer that require administrator-level permission, UAC notifies you. If you are an administrator, you can click Yes to continue. If you are not an administrator, someone with an administrator account on the computer will have to enter their password for you to continue. If you give permission, you are temporarily given the rights of an administrator to complete the task and then your permissions are returned back to that of a standard user. This makes it so that even if you're using an administrator account, changes cannot be made to your computer without you knowing about it, which can help prevent malicious software (malware) and spyware from being installed on or making changes to your computer.
When your permission or password is needed to complete a task, UAC will notify you with one of four different types of dialog boxes. The table below describes the different types of dialog boxes used to notify you and guidance on how to respond to them.
A setting or feature that is part of Windows needs your permission to start.
This item has a valid digital signature that verifies that Microsoft is the publisher of this item. If you get this type of dialog box, it's usually safe to continue. If you are unsure, check the name of the program or function to decide if it’s something you want to run.
A program that is not part of Windows needs your permission to start.
This program has a valid digital signature, which helps to ensure that the program is what it claims to be and verifies the identity of the publisher of the program. If you get this type of dialog box, make sure the program is the one that you want to run and that you trust the publisher.
A program with an unknown publisher needs your permission to start.
This program doesn't have a valid digital signature from its publisher. This doesn't necessarily indicate danger, as many older, legitimate programs lack signatures. However, you should use extra caution and only allow a program to run if you obtained it from a trusted source, such as the original CD or a publisher's website. If you are unsure, look up the name of the program on the Internet to determine if it is a known program or malicious software.
You have been blocked by your system administrator from running this program.
This program has been blocked because it is known to be untrusted. To run this program, you need to contact your system administrator.
We recommend that you log on to your computer with a standard user account most of the time. You can browse the Internet, send e‑mail, and use a word processor, all without an administrator account. When you want to perform an administrative task, such as installing a new program or changing a setting that will affect other users, you don't have to switch to an administrator account; Windows will prompt you for permission or an administrator password before performing the task. We also recommend that you create standard user accounts for all the people who use your computer.
In this version of Windows, you can adjust how often UAC notifies you when changes are made to your computer. If you want to be informed when any change is made to your computer, choose to always be notified. For more information, see What are User Account Control settings?