Did you just type
service apache2 restart
and get stuff like:
* Starting web server apache2 ulimit: 88: error setting limit (Operation not permitted)
(13)Permission denied: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
Unable to open logs
Action 'start' failed.
The Apache error log may have more information.
It is unlikely to be a big crisis. Looks like you don’t have permissions. Apache needs to be started by root user. Are you root? Try
sudo service apache2 restart
You’re welcome :p