Completely uninstall oracle11g steps:
1. Start -> Settings -> Control Panel -> Administrative Tools -> Services to stop all Oracle services.
2. Start -> Programs -> Oracle - OraHome81 -> Oracle Installation Products -> Universal Installer, click "Uninstall Products" - "Expand All", select all directories except "OraDb11g_home1", and delete them.
5. Run regedit, select HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE, and press the del key to delete this entry.
6. Run regedit, select HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services, scroll through the list, and delete all Oracle entries (keys starting with oracle or OraWeb).
7. Run refedit, HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Application, delete all Oracle entries.
8. Delete all keys prefixed with Ora, Oracle, Orcl or EnumOra in the HKEY_CLASSES_ROOT directory.
9. Delete all keys starting with oracle in HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\MenuOrder\Start Menu\Programs.
10. Delete all keys containing Oracle except the Microsoft ODBC for Oracle registry key in HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBCINST.INI.
11. My Computer-->Properties-->Advanced-->Environment Variables, delete the Oracle settings in the environment variables CLASSPATH and PATH.
12. From the desktop, STARTUP (startup) group, program menu, delete all groups and icons related to Oracle.
13. Delete all Oracle-related directories (if you can't delete them, you can delete them after restarting the computer), including:
1.C:\Program file\Oracle directory.
2. ORACLE_BASE directory (oracle installation directory).
3. C:\WINDOWS\system32\config\systemprofile\Oracle directory.
4. C:\Users\Administrator\Oracle or C:\Documents and Settings\Administrator\Oracle directory.
5. Delete the following files ORACLE.INI, oradim73.INI, oradim80.INI, oraodbc.ini, etc. under C:\WINDOWS.
6. If there is a [ORACLE] marked segment in the WIN.INI file under C:\WINDOWS, delete this segment.
14. If necessary, delete all Oracle-related ODBC DSNs
. 15. Go to the event viewer and delete Oracle-related logs. Instructions: If there are individual DLL files that cannot be deleted, ignore them, restart, and start a new installation , When installing, select a new directory, then, after the installation is completed and restarted, the old directory and files can be deleted.
1. Start -> Settings -> Control Panel -> Administrative Tools -> Services to stop all Oracle services.
2. Start -> Programs -> Oracle - OraHome81 -> Oracle Installation Products -> Universal Installer, click "Uninstall Products" - "Expand All", select all directories except "OraDb11g_home1", and delete them.
5. Run regedit, select HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE, and press the del key to delete this entry.
6. Run regedit, select HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services, scroll through the list, and delete all Oracle entries (keys starting with oracle or OraWeb).
7. Run refedit, HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Application, delete all Oracle entries.
8. Delete all keys prefixed with Ora, Oracle, Orcl or EnumOra in the HKEY_CLASSES_ROOT directory.
9. Delete all keys starting with oracle in HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\MenuOrder\Start Menu\Programs.
10. Delete all keys containing Oracle except the Microsoft ODBC for Oracle registry key in HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBCINST.INI.
11. My Computer-->Properties-->Advanced-->Environment Variables, delete the Oracle settings in the environment variables CLASSPATH and PATH.
12. From the desktop, STARTUP (startup) group, program menu, delete all groups and icons related to Oracle.
13. Delete all Oracle-related directories (if you can't delete them, you can delete them after restarting the computer), including:
1.C:\Program file\Oracle directory.
2. ORACLE_BASE directory (oracle installation directory).
3. C:\WINDOWS\system32\config\systemprofile\Oracle directory.
4. C:\Users\Administrator\Oracle or C:\Documents and Settings\Administrator\Oracle directory.
5. Delete the following files ORACLE.INI, oradim73.INI, oradim80.INI, oraodbc.ini, etc. under C:\WINDOWS.
6. If there is a [ORACLE] marked segment in the WIN.INI file under C:\WINDOWS, delete this segment.
14. If necessary, delete all Oracle-related ODBC DSNs
. 15. Go to the event viewer and delete Oracle-related logs. Instructions: If there are individual DLL files that cannot be deleted, ignore them, restart, and start a new installation , When installing, select a new directory, then, after the installation is completed and restarted, the old directory and files can be deleted.