In Windows Vista, User Account Control (UAC) is a feature that was designed to prevent unauthorized changes to your computer. When functions that could potentially affect your computer's operation are made, UAC will prompt for permission or an administrator's password before continuing with the task.
Because malware has greater control of the computer when it is running in administrator mode, UAC was designed to enable more users to run their computers as a standard user rather than as administrator. A computer is more secure against attack if it is running with fewer privileges. When you receive one of the UAC warning pop-ups, Vista is asking for permissions to temporarily elevate into Administrator Mode.
Unfortunately, UAC can quickly frustrate some people and become useless. Users who receive these pop-ups so frequently, become numb to it and begin to automatically answer “Continue” without even reading the message. It is important to read and understand what these messages mean.
There are three different alert messages associated with User Account Control:
Windows needs your permission to continue - This message indicates that Vista requires a change to the operating system and would like you to confirm that you have requested this change. This prompt is to confirm that a piece of malware has not tried to make changes to Vista.
A program needs your permission to continue – This message is notifying the user that a program (in this example Sysinternals) requires administrative permissions in Windows to continue. You should verify the vendor/program that is listed in this window and confirm that this is a valid request. If you do not recognize the program select “Cancel” because it could be malware.
An unidentified program wants access to your computer - This message tells the user that a program that does not have a signature (Digital certificate that Microsoft recognizes as a “Trusted Agent”) is requesting administrative permissions in Windows to continue. You should verify the vendor/program that is listed in this window and confirm that this is a valid request. As with the example above, if you do not recognize the program select “Cancel” because it could be malware.
Microsoft recommends that you do not disable UAC, however if you must turn it off, please refer to our FAQ – How do I turn off UAC in Windows Vista?