How to Manually Uninstall Oracle in Windows 8

Let’s face it – Oracle database is an excellent product but its uninstall process is still mediocre. There are a lot of unknown issues arise when you try to uninstall Oracle database and then try to install it again. We get a lot of queries every week regarding problems installing Oracle products. Most of these problems arise due to improper uninstall of previous Oracle install and presence of old files.

I’ve used the deinstall method to uninstall Oracle database but I face new issues every time. Here is the manual method which I’ve been using for several years now and this will help you remove *all* Oracle software allowing a re-install. To the best of my knowledge – this is the cleanest method to uninstall Oracle database from your Windows machine.

** Use this method at your own risk – It is pretty destructive and if you make any mistake, the outcome will be perilous. 

To uninstall Oracle try the following steps:

• Uninstall all Oracle components using the Oracle Universal Installer (OUI).
• Try using deinstall
• Stop all the Oracle services, which are running.
• Run regedit.exe and delete the HKEY_LOCAL_MACHINE/SOFTWARE/Oracle key. This contains registry entires for all Oracle products.
• If you are running 64-bit Windows, you should also delete the HKEY_LOCAL_MACHINE/SOFTWARE/Wow6432Node/Oracle key if it exists.
• Delete any references to Oracle services left behind in the following part of the registry (HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Ora*).
• Reboot your machine.
• Delete the “C:\Oracle” directory, or whatever directory is your ORACLE_BASE. You might get an error while trying to delete it – it is likely due to a running Oracle Service. Go to the task manager to verify and then stop the service.
• Delete the “C:\Program Files\Oracle” directory.
• If you are running 64-bit Wiindows, you should also delete the “C:\Program Files (x86)\Oracle” directory.
• Remove any Oracle-related subdirectories from the “C:\ProgramData\Microsoft\Windows\Start Menu\Programs\” directory.
• Empty the contents of your “C:\temp” directory.
• Empty your recycle bin.
• Restart your computer

Your machine should now be clean of any Oracle component and you can try installing any other Oracle product again.

If some DLLs can’t be deleted, try renaming them, the after a reboot delete them. It is possible that some of the services do not get deleted even after the above steps. You can delete the services manually using the commands:

• sc query state= all | find “SERVICE_NAME” | Find “Oracle”

This command will list all the service names which start with Oracle. Once you have the service names listed, you can delete them one by one.

• sc delete service_name