Installing Extensions

Thanks to a robust Extension Manager that is built into Firefox (as shown in Figure 7-1), it is a breeze to install extensions.

Figure 7-1. The Firefox Extension Manager.

Here are the steps for installing an extension:

1.	Locate the relevant extension, either at UMO or at another site.
2.	At UMO, select the Install link.
3.	A software installation dialog box launches and requests your permission to install the extension. Because Firefox prides itself on security, this measure is built into Firefox to protect you from possibly installing malicious software by confirming that you actually want to install the file. Other sites that list extensions may require that you click a link, but you should still see the dialog box shown in Figure 7-2, and the remainder of the install instructions listed here should be the same. Figure 7-2. The Software Installation dialog box that launches when you install an extension in Firefox.
4.	After a brief delay, the Install button becomes active, and you should be able to click it. This delay is intentional and was installed as a security measure to protect users from accidentally installing an extension.
5.	The .xpi file now installs in the Extension Manager. A progress meter shows the progress until the extension installation is complete.
6.	After installation, you must restart the browser to enable the extension.

Tip: Another Way to Install Extensions

If you prefer to save the .xpi file to your hard drive, you can drag and drop the saved file into an open browser window, which also triggers the Software Installation dialog box.