Manual Oracle Uninstall

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 re-install. If you make any mistakes they can be quite destructive so be careful.

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.
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*). 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.
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.

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.

If some DLLs can't be deleted, try renaming them, the after a reboot delete them.

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.
```
# oemctl stop oms user/password
# agentctl stop
# lsnrctl stop
```
Alternatively you can kill them using the
kill -9 pid command as the root user.
Delete the files and directories below the $ORACLE_HOME.
```
# cd $ORACLE_HOME
# rm -Rf *
```
With the exception of the product directory, delete directories below the $ORACLE_BASE.
```
# cd $ORACLE_BASE
# rm -Rf admin doc jre o*
```
Delete the /etc/oratab file. If using 9iAS delete the /etc/emtab file also.
```
# rm /etc/oratab /etc/emtab
```