to provide more specific instructions here. The earlier section, "Using Extensions," explains how to get extension-specific help. Updating extensions Firefox automatically checks for updates to (new versions of) your installed extensions about once a day and installs any that are available. If you don't want Firefox to check for or install updates automatically, you can disable this functionality as I discuss in the section on updating Firefox in Chapter 15. You can check for updates manually at any time by clicking the Find Updates button at the bottom of the Extension Manager. Developers update their extensions to add features, to fix bugs, or to make them compatible with a new version of Firefox, which is necessary for the reasons I discuss in "Ensuring Extension Compatibility" earlier in this chapter. When a new version of Firefox is made available, most developers update their extensions to be compatible with the new version, although it may take them two or more weeks. Although Firefox checks for updates to itself each day at the same time it checks for extension updates, Firefox asks you before installing an update that is incompatible with any of your installed extensions. If you proceed with the update, Firefox disables the incompatible extensions, but continues to check for updates to them each day. When an update is available, Firefox installs it automatically and re-enables the now-compatible extension. REMEMBER Each extension has a version number. The developer uses this number to keep track of his extensions. You don't need to worry about it; just remember that the higher the number, the newer the extension. Removing extensions Firefox offers three ways to turn off an extension depending on what you want to do.   A quick complaint about version numbers You're probably already familiar with the concept of software versioning - the higher the number, the newer the software. You're probably also aware - perhaps painfully so - that software companies can't agree on a standard and therefore tend to version things however they please. For example, Microsoft went from Windows 98 to Windows ME to Windows 2000 to Windows XP to the forthcoming Windows Vista. Unfortunately, the situation isn't much better in extension land. Although virtually all developers stick to numeric versions, they use varying levels of complexity. Don't be surprised if one extension's version is 0.4.7.241 and another's is 7.2. My advice is to ignore the numbers entirely and just remember that "higher is newer, and newer is better."   Uninstalling an extension If you just want to get rid of an extension permanently, you can uninstall it from the Extension Manager. Simply select it in the list and click the Uninstall button at the bottom. You must restart Firefox to complete the process. Disabling an extension If you suspect that an extension is causing a problem in Firefox and want to find out, you can disable it temporarily by right-clicking it in the Extension Manager and choosing Disable. Like uninstalling, disabling requires a restart. However, if it turns out that the extension was not the source of the problem, you can re-enable it without having to reinstall it. Right-click it, choose Enable, and then restart Firefox. Disabling all extensions with Safe Mode Disabling is a good way to test a single extension, but what if you have a bunch? You would have to disable each extension one at a time to see whether it's the cause of the problem. That grows old fast, especially if it turns out that none of the extensions is behind the problem. Even worse: What if the