apache in xampp won't turn on - after it worked before

I recently installed Xampp on my windows machine. It worked when I just did it, see here. However, now the apache won't turn on. I realize that I did not close it correctly (did not use xampp_stop), so maybe that could be the cause.

The error I am getting is:

    make_sock: could not bind to address 0.0.0.0:80 
    no listening sockets available, shutting down 
    unable to open logs

How can I get it to work?

Solution

I ended up solving it. Go to the Xampp control panel. Check the "Service" check box. Clicked on "SCM" button. (Or "Service" button, there on the "SCM" button).
Then I clicked on the "Apache" in the list of services. Turned it on.
Now it is labelled as "Running" in the control panel, and "localhost" works.