With Vista and Windows 7, simply click on Start and type in "Restore." "System Restore" will be listed at the top of the Startup Menu.
FWIW, "Restore" is kind of a misnomer. It will -- in most cases -- only "Restore" those thing absolutely necessary for you computer to start up. The other cases, it won't even do that much. It, for sure, won't "Restore" any Data Files you have deleted.