Doom collectors edition

Trying to do add-on's, such as Barney on my Doom Collectors Edition but no luck. I have downloaded it, unzipped it, and I get the message "can't find Doom.wad, Doom2.wad". I am new at this so I need help.

Well, IIRC, the Collector's Edition doesn't have the original .exe files, which are needed when you modify the .wads to use addons. Plus, those addons are ungodly old and probably won't work with the later versions of doom(2).wad.