If you have the error above, and it seems like something else is running on port 80 maybe there is.
I just finished an upgrade from 12.10 to 14.10 and apache couldn’t bind to port 80.,, well when I ran ” netstat -ltnp | grep ‘:80’ ” this is what I got.,
tcp 0 0.0.0.0:80 0.0.0.0:* LISTEN 18635/tntnet
which told me another application “TNTNET” a C++ rapid deployment service runs on port 80,. so I did killall tntnet then I uninstalled tntnet using synaptic and when I issued the apache2 restart command all was wonderful.