Mighty Duck, don't worry, I was not insulted. It's been a while since I used the command prompt and I may have been doing something wrong. I was actually trying to load the wads from the console (hitting the ~ key while in Doom), which may have been my problem. In the past, I always used a WAD loading program, although I don't remember which one. Now I can use all of the wads I downloaded years ago (if I can still find them)
