This happens when you have installed another service running like apache by itself (without any bundle), or WAMP or another bundle that has apache server.
You have to check in your programs if you have 2 different apache installed on your pc and then proceed to uninstall 1 of them. I would uninstall both then install again the one I want to keep (Xampp for example). It's a good practice after you delete/uninstall a program to use tools like Ccleaner to clean the registry of your pc that way you ensure the program is "completely" uninstalled of your pc.
If you have to keep more than one apache instance. Both of then are pointing to the same direction and port by default. You have to change the port that way you can enter to localhost (localhost:8080 by default) and localhost:8083 (another port used to run other apache instance) and so on as many instances of apache you have.
You can read more here:
1) Apache default ip port
2) apache tcp/ip port
3) 2 apache instances on your pc
c:\program files\orangehrm
without your consent. Is it your own computer or it is someone else's? – Álvaro González