title: SQL Developer Status : Failure - I/O Test failed: The Network Adapter could not establish the connection
body: <p>I am a newbie don't know how to use SQL developer. whether I need Oracle database for installing in windows 10 what are these hr and sys users and how to know their passwords. please help me I know this question is asked many times but really, believe me, I have searched a lot but can't find a working solution for it.</p>
  
  <p>Screenshot of my pc:
  <a href="https://i.stack.imgur.com/08Udl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/08Udl.png" alt="enter image description here"></a></p>