What are Windows Updates?
Windows is the operating system of your computer, i.e. the core instructions to the computer as to what to do and how to interact with you. Hackers, criminals who attempt to take control of other people's computers, are constantly trying to find weaknesses in Windows that will allow them access to your system, in the same way that burglars look for open windows and broken door locks on houses. Every time someone succeeds in finding a way to break into Windows, Microsoft release an update (also called "patch") which replaces the vulnerable component with a more secure one; it's like fixing that broken door lock. If your computer is properly configured, it will automatically download and install any Windows updates from the Internet as soon as they become available. Windows Updates also include Microsoft's Malicious Software Removal Tool, which finds and removes some common malicious programs.
How do I check if my computer is correctly configured for Windows Updates?
Go to Control Panel and open Windows Security Center (see the link on the left for more details). If all is well, you will see "Automatic Updates ON" (Windows XP) or "Automatic Updating On" (Windows Vista).
What should I do if Windows Security Center reports a problem?
If Automatic Updates are not configured, it should be fairly easy to correct using a button right next to the warning (see below). For the updates, click on Turn on Automatic Updates (XP); Change Settings, Install updates automatically (Vista).
Is there anything else I need to configure?
Yes, there is. The chances are that as well as Windows, you have some other Microsoft software on your computer, such as Word, Excel or PowerPoint. These programs also need to be updated to remain secure. By using "Microsoft Update", you can ensure that updates for all your Microsoft programs are automatically downloaded and installed. There is no reason not to do this; it won't do any harm if in fact you don't have any other Microsoft programs.
To use Microsoft Update in Windows Vista, go to Control Panel, open Windows Update, then click on “Change settings”. Check that the option marked “recommended” (general update settings) is selected, and then ensure that the box marked “Use Microsoft Update” is ticked, then click OK at the bottom of the window.
If you have Windows XP, you can also make sure all your Microsoft software is updated automatically. Type http://update.microsoft.com into Internet Explorer’s address bar, and click on either “Get Microsoft Update today” or “Upgrade to Microsoft Update”. This will install a small add-in for Internet Explorer (you will need to give the program permission to install), which means that Windows XP will now pick up automatic updates for all your Microsoft programs.