I am a new student in DBA field. I just installed the 9i in my computer. When I installed, I typed in the wrong password for the system. Installation was going fine. But when I try to connect to SQL*PLUS, I typed in the password I entered or manager, it showed error message ORA-12560,TNS protocol adapter error. I tried to uninstalled 9i first and then reinstalled it, but this time the system did not ask for the password. and after the reinstalled finish, I still get the same error message. When I unintalled the 9i, the file Oracle still existed on the C drive. I try to delete it, it says file "oci.dll" can not be deleted. I do know what I can do to delete the folder and reinstall the 9i in my computer.
To uninstall Oracle, follow these steps:
1. Go to Services and make sure that all Oracle services are stopped.
2. Invoke the Oracle Universal Installer (OUI) to uninstall the software.
3. Go to Start->Run and type 'regedit' to invoke the registry editor.
4. Navigate to HKEY_LOCAL_MACHINESoftware and delete the Oracle folder.
5. Right click on My Computer and select Properties. Click to access the Environment Variables. Find the PATH environment variable and edit it to remove any occurences of Oracle directories.
6. Using Explorer, remove any remaining Oracle directories, notably the ORACLE_HOME and C:Program FilesOracle. If there are files you cannot remove, reboot your machine and retry the delete operation.
You should now have a clean machine that you can reinstall Oracle on.