I found following error while I was trying to check whether the dbconsole is running in my Oracle 11g server:
>emctl status dbconsole
EM Configuration issue. C:\oracle\app\product\11.2.0\dbhome_1/nms_dbm not found.
I found that error is caused by incorectly reading of hostname (or %COMPUTERNAME%) variable.
I had to set ORACLE_HOSTNAME properly in order to make dbconsole to work... I added as a system variable.