When Windows Vista is installed on your computer, some—but not all—of its components are available. If any components you need aren’t active, you can turn them on, and, by the same token, if there are components you never use, you can turn them off.
Save any documents you’re working on, and close all your running programs.
Click the Start button, choose Control Panel from the Start menu, choose Programs from the Control Panel, and click Turn Windows Features On Or Off in the Programs window that appears.
If a plus sign (+) appears next to a component, click it to see the items listed under that component group.
To turn a component on, select its check box. To turn a component off, clear the check box.
"Installing Critical Fixes" and "Downloading Free Software" for information about updating existing Windows components or adding components that have recently been released.