"ORA-28547: Connection to Server Failed, Probable Oracle Net Admin Error"

Edit the SQLNET.ora file in a text editor such as Notepad.


Change this line to what is shown below:
#SQLNET.AUTHENTICATION_SERVICES = (NTS)
SQLNET.AUTHENTICATION_SERVICES = (NONE)


Check Path at Env Var


Listener rights issue

Restart Listener

delete listener services in windows

how to delete listener services in windows

regedt32-->hkey_local_machine-->system-->currentcontrolset-->services-->oracle and delete it by delete key.