I've Oracle DB 10g Rel. 2 installed on Windows 2000 server. The database is up and running i.e. everyone can connect to the DB by using any App tool e.g. SQL*Plus, Forms, or Reports. It means that the listener and the service is running. But the problem is that when I try to start the EM I see some error messages on the webpage.

It says:
Enterprise Manager is not able to connect to the database instance. The state of the components are listed below.

Database Instance (Red arrow pointing downwards)
Host workflow-dev
Port 1521
SID orcl
Oracle Home C:\oracle\product\10.2.0\db_1

Agent Connection to Instance (Red arrow pointing downwards)
Status Unavailable

Listener (Green arrow pointing upwards)
Status Up
Host workflow-dev
Port 1521
Oracle Home C:\oracle\product\10.2.0\db_1
Location C:\oracle\product\10.2.0\db_1\network\admin

I've already checked all the services, they are running. And when I execute emctl command I got the following message.

>emctl status dbconsole
Oracle Enterprise Manager 10g Database Control Release
Copyright (c) 1996, 2005 Oracle Corporation. All rights reserved.
Oracle Enterprise Manager 10g is running.

My question is if every thing is workign fine then what is the problem with the EM? Why it is not connecting to the DB?