Manually un-installed Oracle 10g

How we Manually un-installed Oracle 10g - Windows

As a testing box for RMAN and Flashback query, we are supposed to install and perform the required tests on 10g DB. During the first iteration we encountered that OUI was not responding, I believed it to be the security settings on the Windows box. But it was not getting better after changing the security settings on Windows.

Here the steps we took to manually un-install Oracle 10g on Windows 2003 / XP.

On the desktop, we Right Click on MyComputer Icon and selected "Manage".  On the left hand pane, we selected "Service and Applications" from Computer Management.

** Alternatively you can also select Services from Control Panel.

In the next step we Shutdown Oracle Instance and related Oracle Services. Some of them might give errors " Unable to shutdown". It could be because of improper installation.  Now after shutting down the Oracle services, we had to locate the registry entries for Oracle and delete them manually.

We made a backup of registry.

We then clicked on Start --> Run --> Regedit.

Looked for the following entries:
=============================================================================
HKEY_CURRENT_USER\SOFTWARE\ORACLE
HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application\Oracle.oracle
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\OracleDBConsole
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Oracle10g_home
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\OraclService
=========================================================================
Deleting  the above entries from the registry required a reboot, so we did a Reboot of the windows box.
Some entries in the registry like registering of some components required cleaning software. We did it using "CleanMyPCRegistry”. This removed any discrepancies in the registry.

Now in the next step we deleted the physical directories.

C:\Oracle

Deleted the Oracle Program Files directory:
C:\Program Files\Oracle
Deleted the Oracle Start Menu shortcuts directory:
C:\Documents and Settings\All Users\Start Menu\Programs\Oracle

Removed Oracle references from the path. To edit the path we went to:

Start->Settings->Control Panel->System->Advanced->Environment Variables

We edited both of the environment variables user PATH and system PATH. Remove any Oracle references in them.

Then we removed Oracle.DataAccess and any Polic.Oracle files from the GAC which is at:
C:\Windows\assembly\

We also received an error while removing the $ORACLE_HOME/bin directory. While un-installing oci.dll (Oracle Call interface could not be deleted.

To resolve this, we renamed the Oracle/bin folder and re-boot the machine. After reboot, we are able to delete the oci.dll. We then proceeded with the proper installation of Oracle 10g R2.