Umbraco provides an easy mechanism to create your own CUSTOM ERROR 404 pages for your website.
These are the steps needed :
1. Create a Page inside your Umbraco content tree. This would be your error landing page.
2. Note down the Page Id of this page created. You can get this from the property tab or by hovering the move over the page content tree.
3. Go to the application folder. Go to Config -> Open umbracoSettings.config file. You will find a section in this file as below :
<errors> <!-- the id of the page that should be shown if the page is not found --> <!-- <<span class="hiddenSpellError" pre="">errorPage</span> culture="default">1</errorPage>--> <!-- <errorPage culture="en-US">200</errorPage>--> <error404>1</error404> </errors>
4. Change the ‘1’ in <error404>1</error404> to the node id of your new page.
5. Also, Un-comment the <errorpage> nodes. Change the default ‘1’ , to the Page Id which you have noted down.
6. If you are using a Multilingual Site, then create an error landing page for each language. And have the Id specified for each culture.
From now on , ‘The Ugly Looking Page ‘ would not show up each time a user hits a broken link !