Here is the manual for the P4P800-E Deluxe.
(edit: have to go to their support site. See below)
There are a ton of P4P800 boards, so this may not be exactly yours, but it is the only -E I could find.
However, all of them are old socket 478 boards.
To do more searching, go to the Asus support sitehttp://support.asus.com/download/download.aspx?SLanguage=en-us
Let us know what else help you need.