Can't relaunch Finder and the menubar is missing I booted up my MacBook Air (running Mac OS X Lion) and the desktop doesn't have a menubar.  I used option+right-click to relaunch Finder and there isn't an option to relaunch it.  When I launch an application the menubar shows up.  When I cmd+q to quit the application the application's window closes but the menubar then defaults to the last currently open application.  Even if it's on a different virtual desktop.  

When I reboot the computer I notice that the keyboard is no longer backlit by default.  The keyboard only becomes backlit after I correctly enter my password.  I don't know if this is related to the problem stated in the first paragraph.  It may or may not be relevant.  I don't know.  

Any thoughts or ideas?  I've never seen a desktop in Mac OS X that didn't have a menubar.  

To recap: No menubar, no date, time, Spotlight icon etc. when all applications are closed.  They show up when I launch an application.  Option to relaunch Finder is gone.
Try quitting Finder using Activity Monitor (in Utilities). It's in Launchpad there too. Scroll down the list of processes till you see Finder, click it and then choose Quit Process from the toolbar. Choose "Force Quit" at the dialog.

If Finder isn't in the list of applications in Activity Monitor, you can manually start it. It's located at /System/Library/CoreServices/Finder.app. If you can't get to it by browsing (because Finder isn't running!) you can always use Terminal. It's in Utilities too. Just type

open /System/Library/CoreServices/Finder.app


into the window and hit return.