How do I create a custom 404 page?

A custom 404 page is a page with a message you create which a user sees when a page is not found. Drupal custom 404 pages are associated with your Site information.

To create a custom 404 page:

1. First, create a basic page and add your message (see, How do I add a new Basic page?)
2. Click Configuration, then System, then Site information.
3. At the bottom of the overlay, in Error Pages there are two fields.
4. In the Default 404 (not found) page  enter the name of your new 404 page.
5. You can also follow the same process to add a custom 403 Access Denied page.