Yesterday I gave my decision to upgrade my 10G OCA certificate to OCP. For preperation I need an EE or PE 10G database and I have two database installed (XE and 10.1.0.1 EE (SID= ORACOS) )on my Windows XP Pro Machine. The installation order was first XE next 10.1.0.1 EE and after installation I configured the listener of 10.1.0.1 with another port rather than 1521 because of the port conflicts. Moreover I configure the listener start from the XE home and I didn’t configure EM for 10.1.0.1 database from the installation till today.
When I need EE what i did is firts I changed the ORACLE_HOME to 10.1.0.1 home from XE home and I changed the ORACLE_SID to ORACOS then I started EM with
>emctl start
Enterprise manager started but when I went to EM page database status was unavailable and needs recovery.
I said recover database and this button took me the host and database credential entry page. I gave local administrator for host and sys for database unfortunately I took the error “RemoteOperationException: ERROR: Wrong password for user”. I changed the password for the local administrator bu nothing has changed after googling I found a solution at an orafaq forum thread . The solution is below and worked well and took me to the next trouble 
Solution for “RemoteOperationException: ERROR: Wrong password for user” error :
If you are on windows: Go to Control Panel–>Administrative Tools–>Local Security Policy–>Local Policies–>User Rights Assignment–>U will see in the policy as “Log on as a batch Job–>right click–>Properties–>add user or groups–>give your OS username.
The next trouble was “Io exception: The Network Adapter could not establish the connection”
I checked the listener_oracos it was working well. For a try I restarted both dbconsole and listener but the error was there again. What could be the problem ?
Here comes the solution from the survivor Metalink. Note:273758.1 . The problem is that I did a default installation for database and made changes to default listener configuration but I did not reflect it to other hard coded configuration files such as enterprise manager config files.
To solve the problem I change the default entries (oracle_listener,Port,LsnrName,ListenerOraDir ) on the file ORACLE_HOME/hostname_sid/sysman/emd/targets.xml and port entries for the parameter oracle.sysman.eml.mntr.emdRepPort, oracle.sysman.eml.mntr.emdRepConnectDescriptor on the file ORACLE_HOME/hostname_sid/sysman/config/emoms.properties
and restart the dbconsole. Guess what happened ? I started to sing the song “Yesterday All my troubles seems so far away …..”
Moral of the story; If you make a configuration change, reflect the change to all of the files related with your change.
Now it is time to prepare for OCP exam. I hope In 2-3 weeks time i will take the exam and will write the interesting OCP topics here.
