How to update Drupal

From time to time Drupal may have a security update and you should update your site each time a new release is ready. It is very easy and painless to do.

login, goto administer > site configuration > site maintenance
change site status to off-line and save it...
I generally just stay logged in

Then-- fire up the FTP program and delete all Drupal files except the "sites" folder. (it has your stuff in it)
Then-- copy all the new Drupal files to the server except the "sites" folder(the new one has nothing in it)
Then-- run update.php
Over to the far left side of the admin_menu under the icon. click "run updates", click "continue", click "update".
--or--
Goto http://www.example.com/update.php , click "continue", click "update".
Then-- put the site back on-line.  NOTE: the reason for taking the site off-line is to stop database activity...

What if it just won't work after the new files are uploaded?
Double check to see that ALL the folders and files are there. Usually if it won't work, you are missing a folder or a file.