Replication on Windows 2k

[Andrea Petrini]

I need to set up a replication between a Mysql 3.23.54 as Master and a 3.23.58 as Slave, running on two Windows 2k servers.
The slave's my.ini is something like:
...
[replication]
master-host=<IP address>
master-user=<user name>
master-password=<user pass>
server-id=x
replication-do-db=<db name>

I haven't no error messages on starting the slave db, but the replication doesn't work.
If i try manually with mysqladmin start-slave, it says: "Mysqladmin: Error starting slave: this server is not configured as slave, fix in config file or with CHANGE MASTER TO".
I tried using the way of CHANGE MASTER TO, but I obtain the same message.
Thanks to everyone wants to help me.
Andy.