Here I am going to illustrate the procedure to patch oracle 19c database in windows enthronement, to apply APRIL 2021 CPU patches (19.11) RU (release update).

Download Windows Database Bundle Patch (19c) 19.11 from Oracle Support website.

Download the latest OPatch utility:

Ensure your run CMD as administrator:

Check your environment variables:

set PATH=%ORACLE_HOME%\perl\bin;%PATH%

set ORACLE_HOME=D:\WINDOWS.X64_193000_db_home

set PERL5LIB=

Stop Distributed Transaction Coordinator:

net stop msdtc

Go to the directory where the patch is downloaded

D:

cd D:\19.11.windows_patch\32409154

Apply the patches using the downloaded Opatch utility and copy it under your $ORACLE_HOME/OPatch directory:

D:\WINDOWS.X64_193000_db_home\OPatch\opatch.bat apply

Startup the Oracle services again:

Post-Patch activity:

sqlplus / as sysdba

SQL> startup

SQL> alter pluggable database all open;

SQL> exit;

In CMD session (run it as administrator):

D:

cd D:\WINDOWS.X64_193000_db_home\OPatch\

datapatch -verbose

Then, check the registry that the patch is successfully applied:

select * from dba_registry_sqlpatch;