I added apache to my Windoze setup recently. My windoze machine also has skype. This is when a discovered a nasty interaction. I found it on a forum at http://forums.devarticles.com/programming-tools-11/os-10048t-11921.html. Skype uses port 80! Yes, it even uses 443 (the https port) as well. Luckily these are the default settings and can be changed. And change them you must otherwise apache mysteriously fails to start. The Windoze event log reveals nothing. I eventually found it was a port conflict by trying to start httd from the DOS prompt.