You can configure your apache server to not use the default 404 page and use one of the pages made by you.
Read the link below to find out how to do it
thanks for your reply but i do know how to change the 404 file not found page
what i do want to know is how i can make it look like it's a page from vbulletin, to include my vbulletin footer and header in it, like the one you use here