Microsoft Events Sharepoint - MOSS, SQL, WINDOWS Events and resolutions in one place

If You want branding AccessDenied.aspx (_layouts) site You should make modifications in "simple.master". Like most master pages, the simple.master controls the look and feel or more than just a single page. In fact, it controls the look and feel of seven pages in the _layouts folder:

 "C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\LAYOUTS

 Any changes could have impact to application level or for one site collection only.

Precisely how to change "simple.master" and contraindications are written in Microsoft article. Please see here:

http://support.microsoft.com/kb/944105/en-us