Essential PC security tips User account controls

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This article, Essential PC security tips, was last updated on 02 February 2009 and is now out of date and held in our online archive for reference. Explore our latest Technology articles.

Windows Vista’s User Account Controls (UAC) prevents unauthorised access to your computer by asking for your permission or for an administrator password before performing functions that could affect your computer’s performance. 

Here are some symbols you’ll encounter:

Multi-coloured shield symbol

This symbol means that a Windows function or program that can affect other users of your computer needs your permission to continue.

Check it’s a program you want to run before clicking OK.

Exclamation markshield symbol

A program that’s not part of Windows needs your permission to continue.

Check that you recognise the program and its publisher before you allow it to run.

Question mark shield symbol

An unidentified program wants access to your computer. 

This doesn’t necessarily mean it isn’t what it claims to be, only that it doesn’t have a digital signature to identify it. 

Exercise caution and only run it if you got it from a trusted source.

Red crossed shield symbol

This symbol indicates that the program is blocked. 

To run this program you’ll need to contact your computer’s administrator and ask them to unblock it.