In other instances you may simply want a newer version of Internet Explorer. To get one, visit Microsoft Update, Windows Download Center, or Microsoft's Internet Explorer site.

Your operating system isn't the only software you need to keep patched. In the old days, users commonly had to find third-party security updates on their own. In more-recent years, however, as criminal hackers have begun targeting common desktop applications, vendors of multimedia apps in particular have gotten better at pushing out their own security patches. Here's a look at the update process for some common types of desktop software.

Firefox: Mozilla silently and automatically downloads its browser security updates in the background; Firefox then installs the update the next time you launch the browser. You can check for updates whenever you want by clicking Help, followed by Check for Updates. Full-version updates (say, an upgrade from Firefox 2 to Firefox 3), however, still require a clean installation from Mozilla.

iTunes and QuickTime: Whenever you launch an Apple application within Windows, Apple does a quick check and then notifies you of the latest release for iTunes or QuickTime (if you aren't already running it). You can also request a update by clicking Help, and then Check for Updates. Occasionally, Apple will push out a notification of a new security update for iTunes and/or QuickTime. When it does, a dialog box will pop up to explain what the update includes. Unfortunately, Apple has been known to --such as Safari and Bonjour for Windows--with these updates, regardless of whether you already have these apps installed. If you don't want these extra programs, simply uncheck their boxes before installing the update.