1. First we need to download deinstall tool from oracle site.
The deinstall command removes standalone Oracle Database installations,
Oracle Clusterware and Oracle ASM from your server, and also Oracle Real Application
Clusters (Oracle RAC) and Oracle Database client installations.
The Deinstallation Tool (deinstall) is available in Oracle home directories after installation. It is located in the $ORACLE_HOME/deinstall directory.
The deinstall command uses the information you provide, plus information gathered from the software home to create a parameter file. You can alternatively supply a parameter file
The deinstall command stops Oracle software, and removes Oracle software and configuration files on the operating system.
To download the Deinstallation tool:
a. Go to the following URL:
b. Under Oracle Database 11g Release 2, click See All for the respective platform for which you want to download the Deinstallation Tool.
The Deinstallation Tool is available for download at the end of this page.
c. you can search in google as key word
"Oracle De-install Utility (184.108.40.206.0) for windows"
2. log in as a Administrator
3. Unzip Deinstallation tool on your machine than follow below command.
4. install it.
Deinstallation Tool (deinstall) is available in Oracle home directories after installation.
It is located in the $ORACLE_HOME/deinstall directory.
6. set your Oracle 11gR2 home and than use below syntax:
C:\Documents and Settings\era-1>D:
D:\>set ORACLE_HOME= D:\oracle\product\11.2.0\db_1
D:\>deinstall -home D:\oracle\product\11.2.0\db_1
in unix like below
$ cd /u01/app/oracle/product/11.2.0/dbhome_1/deinstall
for more info about deinstall tools use:-