As information, I did not use the user dba again because I thought my problem was using root and I created another user (dba). Then I saw this was not the problem and I used root to set up the server.
What I have been learning and missed up with during setting up the server:
Root must have a password and it should respect some conditions like having a minimum of 8 characters and so on.
The server id is the server name we give while setting up the server but not the server_id we set in the my.ini file while setting up Mysql.