Note:
This guide was written for Oracle 10g running on a Windows server but the process is identical with the exception of how you stop and start the Enterprise Manager service.
When changing the sysman account password, which run the Oracle Enterprise Manager Application, you will need to stop the OracleDBConsole<SID> service from the Services Control Panel applet. This will keep the sysman account from getting locked out.
Log into sqlplus as the user sys then type:
ALTER USER sysman identified BY <new password>
Navigate in Windows Explorer to:
<ORACLE_HOME>\<localhost.domain_SID>\sysman\config
(Where localhost.domain_SID is specific to your installation environment.)
Open the file named emoms.properties in Wordpad
Located the value:
oracle.sysman.eml.mntr.emdRepPwd=<encrypted value>
(Where <encrypted value> is a random string of numbers and letters)
Change this to encrypted password to your new sysman password
Locate the Value:
oracle.sysman.eml.mntr.emdRepPwdEncrypted=TRUE
Change it to:
oracle.sysman.eml.mntr.emdRepPwdEncrypted=FALSE
Note:
Once you start the OracleDBConsole<SID> service it will change this cleartext password to its encrypted value.
Now start OracleDBConsole<SID> services that you stop before.
Note:
If the sysman or any other account becomes locked, you can unlock it with this command.
ALTER USER account unlock;