For Complete Oracle 19c uninstallation, you need to

1. remove registers
2. remove the users created during Oracle installation
3. remove path environment

Delete Oracle folder from windows, and restart. Now you can re-install Oracle.

The trickiest part here is to remove the registers. For details read Uninstall Oracle 19c: https://www.swapreference.com/oracle/19c/uninstall-oracle-19c-win-10/

I have followed this tutorial.

Basically Oracle installation does : Create register, Path environment, and create Database User and Groups. You need to remove them manually, as Oracle did not provided Uninstaller.

For Complete Oracle 19c uninstallation, you need to

1. remove registers
2. remove the users created during Oracle installation
3. remove path environment

Delete Oracle folder from windows, and restart. Now you can re-install Oracle.

The trickiest part here is to remove the registers. For details read Uninstall Oracle 19c:

I have followed this tutorial.

Basically Oracle installation does : Create register, Path environment, and create Database User and Groups. You need to remove them manually, as Oracle did not provided Uninstaller.

Information Source: https://www.swapreference.com/oracle/19c/uninstall-oracle-19c-win-10/