Manually
- START -> RUN -> Services.msc
- Locate all Ora* services & click on STOP
- Start -> RUN -> Regedit
- Locate HKEY_LOCAL_MACHINE folder in the registry
- Open Software folder
- Delete the Oracle folder under Software
- Open System folder in HKEY_LOCAL_MACHINE
- Open CurrentControlSet folder within the System folder
- Open Services
- Delete all keys related to Oracle. Every key starts with “ORA..”
- Close the regedit
- Delete ORACLE_HOME folder
- Delete the Oracle folder in Program Files
- Reboot
Uninstall all Oracle components using the Oracle Universal Installer (OUI).
- Delete the HKEY_LOCAL_MACHINE/SOFTWARE/ORACLE (and HKEY_LOCAL_MACHINESOFTWAREWow6432NodeORACLE on 64bit) key which contains registry entries for all Oracle products by using regedit.
- Delete any references to Oracle services/components in the following registry location: HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/. Looks for key entries that starts with “Ora” which are obviously related to Oracle.
- Reboot the workstation.
- Delete the ORACLE_BASE directory. (i.e C:Oracle)
- Delete the directory C:Program FilesOracle.
- Empty the temp directory.
- Empty the recycle bin.