Abbreviated as UAC. In Windows Vista, User Account Control 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. There are four different alert messages associated with User Account Control:

  • Windows needs your permission to continue
  • A program needs your permission to continue
  • An unidentified program wants access to your computer
  • This program has been blocked