Macbook won't shut down because finder won't quit

Question

Macbook  10.5  Leopard, purchased  October 2007.
Tried to shut down
Popup says "logout has timed out because application finder has failed to quit, to try again quit finder and choose logoput from the apple menu"
I tried  ..... and nothing.  Can't shut down.
I tried command option escape  and that doesn't work.
Tried to  force quit, and  that doesn't work. 
Somewhow   finder is still running no matter what and hence I can't shut down. This is very frustrating
Is there  any way I can get the computer to have everything  go dark and shut down?  All the obvious instructions  don't work
I have had to force quit  in the past maybe 2 or 3 times in the past.    No biggie.  But this problem of  not being able to shut down even after force quit is new.
Nothing is connected to the   macbook except the  external monitor, which has always been there.

Answer 1

If any of the apps won't quit on you in future, try ti kill them in Terminal:
killall Finder
then hit enter
If you don't know the official app name (how OS SX sees it), go to COMMAND_OPTION_ESCAPE and see the official name in the running app list.
The power button method above works 100%, but will bypass saving of session states for all services, so your OS X could be unstable after reboot and won't remember some settings you had prior to shuting down. Use it only as a last resort.