"This page does not exist" Pages

[Rokkuman]

How do I make my own custom "this page does not exist" page? I'm running the site off my own computer, so it's not reliant on the host (well, technically it is... but... shut up.)

[Zack]

You're using Apache? Then I'm pretty sure there's a directory with files named something like...
"error404.html" for the Error 404 - Not found page
Look it up in the Apache readme.
[EDIT]
Scratch that...you'll need to edit your .htaccess file. If you don't have one, you'll need to use MSDOS EDIT to make it, because Windows can't make files that have only an extension...so, anyway, name it .htaccess.
Then just put a line at the bottom saying...
ErrorDocument errorCode localPath
Where errorCode is the http error code (404 is not found) and localPath is something like /errors/error404.html...which is the path to the error page.