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Oracle® Database Installation Guide
10g Release 2 (10.2) for Microsoft Windows (x64)

Part Number B15681-01
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6 Removing Oracle Database Software

This chapter describes how to remove Oracle databases, instances, and software:


Always use Oracle Universal Installer to initially remove Oracle components. To avoid installation and configuration problems with new Oracle installations, follow the instructions in this chapter.

See Also:

  • Oracle Database Oracle Clusterware and Oracle Real Application Clusters Installation Guide for information about removing an Oracle Real Application Clusters installation

  • Oracle Database Companion CD Installation Guide for Microsoft Windows (32-Bit) for information about removing an Oracle HTML DB installation

  • Component-specific documentation for individual requirements and restrictions

Removing Oracle Cluster Synchronization Services (CSS)

The first time you install Oracle Database, if you selected Automatic Storage Management as a storage and recovery option, Oracle Universal Installer configures and starts a single-instance version of the Oracle Cluster Synchronization Services (CSS) service.

If you did not choose Automatic Storage Management as a storage/recovery option, you can delete OracleCSService. To delete this service without deleting the Oracle home, perform the following:

  1. Open a command prompt window.

  2. Temporarily set the ORACLE_HOME environment variable. For example:

    set ORACLE_HOME=c:\oracle\product\10.2.0\db_1
  3. Run the localconfig batch file with the delete option to delete the OracleCSService service. For example:

    c:\> oracle\product\10.2.0\db_1\bin\localconfig delete


You do not need to complete this step if you are removing the Oracle home.

See Also:

"Running Oracle Cluster Synchronization Services (CSS) from a Different Oracle Home" for information on configuring the service to use a different Oracle home

Removing All Oracle Database Components

Use Oracle Universal Installer to remove Oracle components from the inventory on the computer. Afterwards, you need to manually remove the remaining components.

Do not delete Oracle home files or directories (for example, using Windows Explorer or the command prompt) without first using Oracle Universal Installer unless you exit Oracle Universal Installer during an installation. Otherwise, the components in the Oracle home remain registered in the Oracle Universal Installer inventory. If you manually delete Oracle home files and you attempt an installation in the same Oracle home, then some or all of the selected components may not be installed or properly configured.

Oracle Universal Installer does not register the installation in its inventory if the installation is unexpectedly interrupted. However, files may have been copied to your Oracle home. Remove these files manually and restart the installation.


You can use Oracle Database Configuration Assistant to remove an instance and related services. For information about Oracle Database Configuration Assistant, see "Installing Oracle and Building the Database" chapter of Oracle Database 2 Day DBA.

This section contains these steps:

  1. Stopping Oracle Services

  2. Removing Components with Oracle Universal Installer

  3. Manually Removing the Remaining Oracle Database Components

Stopping Oracle Services

You must first stop the Oracle services before removing Oracle components.

Follow these steps:

  1. Open the Windows Services utility: From the Start menu, select Programs, then then Administrative Tools, then Services.

  2. If any Oracle services (names begin with Oracle or Ora) exist and have the status Started, then select each of the services, and click Stop.

  3. Exit Services.

See Also:

The Microsoft online help for more information about stopping services

Removing Components with Oracle Universal Installer

To remove components with Oracle Universal Installer in interactive mode:

  1. Ensure that you first follow the instructions in the "Stopping Oracle Services" section.

  2. Start Oracle Universal Installer: From the Start menu, select Programs, then Oracle - HOME_NAME, then Oracle Installation Products, then Universal Installer.

    The Welcome window for Oracle Universal Installer appears.

  3. Click the Deinstall Products button.

    The Inventory window appears.

  4. Expand the tree of installed components until you find the components to remove.

    For example, if you installed a database with the Enterprise Edition option and later installed additional components with the Custom option, expand the Oracle home component to display all the components installed in the Oracle home.

  5. Select the components to remove.

  6. Click Remove.

    The Confirmation window appears.

  7. In the Confirmation dialog box, click Yes to remove the selected components to initiate the removal process.


    A message may appear indicating that removing some components may cause other components to not function properly.

    After the components are removed from your computer, the Inventory window appears without the removed components.

  8. Click Close to close the Inventory window.

  9. Click Cancel to exit Oracle Universal Installer.

  10. Click Yes to confirm that you want to exit.

Manually Removing the Remaining Oracle Database Components

Oracle Universal Installer does not remove all Oracle components. After using Oracle Universal Installer to remove Oracle components, you need to manually remove remaining registry keys, environment variables, Start menu options, and directories.

  1. Removing an Automatic Storage Management Instance

  2. Removing Oracle Keys from the Microsoft Registry Editor

  3. Updating the System Variable Path

  4. Removing Oracle from the Start Menu

  5. Removing Oracle Directories


In rare situations, you may want to correct serious system problems by completely removing Oracle components manually from the computer without first deinstalling with Oracle Universal Installer. Do this only as a last resort, and only if you want to remove all Oracle components from your system.

Removing an Automatic Storage Management Instance

To remove an Automatic Storage Management (ASM) instance running in the Oracle home after the database has been removed, perform the following steps:

  1. At the Windows command prompt, set the ORACLE_SID environment variable to the SID for the Automatic Storage Management instance. For example:

  2. Start SQL*Plus and connect to the Automatic Storage Management instance as the SYS user:

    SYSTEM_DRIVE:\> sqlplus sys/sys_password as sysdba
  3. Enter the following command to determine whether any Oracle database instance is using the Automatic Storage Management instance:


    This command lists all of the database instances that are using this Automatic Storage Management instance. This command only lists database instances that are running. It is possible that other instances are associated with the Automatic Storage Management instance, but they are not currently running.

    If you removed a database from this Oracle home but the output from the command shows that this Automatic Storage Management instance is supporting a database instance in another Oracle home, do not remove the Automatic Storage Management instance or the Oracle home.

  4. If there are no database instances associated with this Automatic Storage Management instance, drop the disk group associated with this instance.


    Dropping the Automatic Storage Management disk group makes the disk device available for use with another Automatic Storage Management instance if required. However, all data in the disk group is lost. Make sure that no other database instance requires any data from this disk group before you drop it.

    1. Identify the disk groups associated with the Automatic Storage Management instance:

    2. For each disk group that you want to delete, enter a command similar to the following:

  5. Shut down the Automatic Storage Management instance and exit SQL*Plus:

  6. At the command prompt, enter the following command to remove the Automatic Storage Management service:


Removing Oracle Keys from the Microsoft Registry Editor

Oracle Universal Installer creates Windows services for Oracle components during installation but it does not delete all the services created by Oracle Net Configuration Assistant and Oracle Database Configuration Assistant during deinstallation. In addition, Oracle Universal Installer does not delete several other Registry Editor keys. You need to remove any existing registry keys manually by following the instructions in one of the following sections:


Use Microsoft Registry Editor at your own risk. Incorrectly using the Registry Editor can cause serious problems and may require reinstallation of your operating system.

Removing Only the Oracle Net Service Registry Key

To remove only the Oracle Net Service registry entry (if it exists):

  1. Log in as a member of the Administrators group.

  2. Make sure that you have stopped Oracle services by following the instructions in the "Stopping Oracle Services" section.

  3. From the Start menu, choose Run, and in the Open field, enter the following command:

  4. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services and delete the OracleHOME_NAMETNSListener registry entry. Oracle Universal Installer automatically deletes all other Oracle Net services.

  5. Exit the Registry Editor.

  6. Restart your computer.

Removing All Oracle Registry Keys


These instructions remove all Oracle components, services, and registry entries from your computer. Use extreme care when removing registry entries. Removing incorrect entries can break your system. Do not delete any database files under ORACLE_BASE\ORACLE_HOME\DB_NAME until you have completed these instructions.

To remove all Oracle registry keys from a computer:

  1. Log in as a member of the Administrators group.

  2. Make sure that you have stopped Oracle services by following the instructions in the "Stopping Oracle Services" section.

  3. Start the registry editor at the command prompt:

    SYSTEM_DRIVE:\> regedit

  5. Delete keys that begin with Ora, Oracle, Orcl, or EnumOra.

    This collection of keys includes those that begin with the following:

    • EnumOraHomes

    • OracleConfig

    • OracleDatabase

    • OracleHome

    • OracleInProcServer

    • OracleProcess

    • ORADC



    • OraOLEDB

    • OraPerfMon




  7. Delete the ORACLE key.

  8. Go to HKEY_CURRENT_USER\Software.

  9. Delete all Oracle keys, including Oracle-HOME_NAME entries under: Microsoft\Windows\CurrentVersion\Explorer\MenuOrder\Start Menu\Programs.

  10. Go to HKEY_LOCAL_MACHINE\SOFTWARE and search for the ORACLE Group key.

    Select ORACLE and note the value of the inst_loc key. This is the location of Oracle Universal Installer. The default location is c:\Program Files\Oracle\Inventory. If this value is different, make a note of it so that you can delete it later.

  11. Delete the ORACLE Group key.


  13. Expand all the subkeys under ODBC and remove any Oracle-related ODBC driver keys, except for the Microsoft ODBC for Oracle key.

    For example, the ODBC\ODBCINST.INI directory lists keys for each Oracle home.

  14. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services.

  15. Delete all keys under this branch that begin with Oracle or OraWeb.

  16. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ Eventlog\Application.

  17. Delete all keys under this branch that begin with Oracle.

  18. Exit the registry editor.

  19. Restart your computer.

Updating the System Variable Path

Check the Path environmental variable and remove any Oracle entries.

  1. Open System from the Control Panel.

  2. In the System Properties dialog box, click the Advanced tab, then click the Environment Variables button.

  3. Select the system variable Path and edit the Path variable to remove any Oracle entries.

    For example, remove Oracle entries that contain ORACLE_BASE\ORACLE_HOME in the Path variable. You may see a Path variable that contains entries similar to the following:


    If the JRE path was installed by Oracle, remove it.

  4. If there is a CLASSPATH variable that was set for Oracle, delete it.

  5. If there are any other Oracle variables set, remove them: ORACLE_HOME, ORACLE_SID, TNS_ADMIN, JSERV, or WV_GATEWAY_CFG.

  6. Save your changes and then exit the Control Panel.

Removing Oracle from the Start Menu

Check the Start menu for any Oracle entries and remove them.

Follow these steps:

  1. Select Start, then Programs, then Oracle - HOME_NAME.

  2. Right-click Oracle - HOME_NAME, and from the menu, select Delete.

You can also remove Oracle menu entries by using the following method:

  1. Right-click the Start button to display the pop-up menu.

  2. Select the Explore All Users option.

  3. Under Documents and Settings, expand the \Start Menu\Programs folder.

  4. Right-click and delete the Oracle - HOME_NAME folder.

Removing Oracle Directories

After removing all Oracle registry keys and restarting the computer, delete any existing Oracle directories and files.

Use My Computer or Windows Explorer to delete the following directories:

  1. Delete the SYSTEM_DRIVE:\Program Files\Oracle directory.

  2. Delete all ORACLE_BASE directories on your hard drive.

  3. If Oracle Universal Installer was installed in a location other than the default, delete this directory.

  4. Remove any Oracle temporary directory files from SYSTEM_DRIVE:\Documents and Settings\username\Local Settings\Temp.