In order to keep the performance of your PC to a good level, it is important to download and install the latest updates for your operating system from Microsoft. This can be done by using the 'Windows Update' utility.
To access the 'Windows Update' utility, click on 'Start', 'All Programs' and 'Windows Update'.
In Windows XP this will take you to an Internet Explorer web page, from here install the Windows update software if needed. You will then get an option to install updates, to simply keep up to date with the latest updates, click on 'Express' (See screenshot below). A list of updates will be retrieved and prioritised, Windows will then automatically download and install them for you.
In Windows Vista the 'Windows Update' application will load up a Windows pane, and from here you can follow the steps to download the updates or click on 'Check for updates' as seen in the screenshot below:
Installing the recommended updates from Microsoft ensures your PC has the latest fixes for operating system bugs and the latest security updates to help keep your PC safe from Internet security threats.Be sure to set updates to download and install on an automatic basis if possible, see the 'Security Centre' guide on how to do this.
Note: An Internet Connection is required to download updates. If you do not have an Internet Connection, then it is possible to order a Service Pack CD (updates to a certain date) from Microsoft by contacting them.