If your WampServer is not working or inactive and if you test your port 80, you might get above messages.
[From menu, select =>Apache=>Services=Test Post 80].
If you get a message like this: "Your port 80 is not actually used", at the time of port 80 test, here your port 80 is not using by any program. Post 80 needed by WampServer for its working.
Now, go to Wamp server icon=>Apache=>Service =>Install Service.
Now you will get a message like this: "Your port 80 is available, install will proceed. Press Enter to continue… " . Just press ‘Enter’ key from your keyboard.
Again, go to Wamp server icon=>Apache=>Service =>Start/Resume Service.
Now you can use your WampServer as active.
You may read more about WampServer errors here: