A number of people have contacted me regarding problems uninstalling Oracle products. The two methods listed below should only be used as a last resort and will remove all Oracle software allowing a reinstall. If you make any mistakes they can be quite destructive so be careful
Windows
UNIX
Windows
In the past I've had many problems uninstalling all Oracle products from Windows systems. Here's my last resort method:
Uninstall all Oracle components using the Oracle Universal Installer (OUI).
Run regedit.exe and delete the HKEY_LOCAL_MACHINE/SOFTWARE/ORACLE key. This contains registry entires for all Oracle products.
Delete any references to Oracle services left behind in the following part of the registry:
HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Ora*
It should be pretty obvious which ones relate to Oracle.
Reboot your machine.
Delete the "C:\Oracle" directory, or whatever directory is your ORACLE_BASE.
Delete the "C:\Program Files\Oracle" directory.
Empty the contents of your "c:\temp" directory.
Empty your recycle bin.
At this point your machine will be as clean of Oracle components as it can be without a complete OS reinstall.
Remember, manually editing your registry can be very destructive and force an OS reinstall so only do it as a last resort.
UNIX
Uninstalling all products from UNIX is a lot more consistent. If you do need to resort to a manual uninstall you should do something like:
Uninstall all Oracle components using the Oracle Universal Installer (OUI).
Stop any outstanding processes using the appropriate utilities:
