I’ve try it with Oracle version 8 and above.
- Uninstall Oracle with Universal Installer.
- After finish, Restart your computer and pres F8 to go to Save Mode.
- Delete Oracle Folder Directory.
- Go to Regedit (type regedit in Run window) and find HKEY_LOCAL_MACHINE -> SOFTWARE -> ORACLE. Delete ORACLE.
- Still in regedit, find HKEY_LOCAL_MACHINE -> SYSTEM -> CurrentControlSet -> Services -> And delete your Oracle service (It can be your Oracle Listener or your Oracle Service).