TNS/SQL*Net problem

Question

Sorry if this is a dim question but I have gone through the wise words in other threads and haven't managed to apply them to my situation - either I'm trying the wrong things, being stupid or there's something odd going on.
OS: Windows XP (Media Centre)
DB: Oracle 10.2.0
Proprietary application accesses this using a straightforward x/y@db_name connect string.
This was working quite happily until a registry cleaner decided to target some registry entries and now
a) the listener service doesn't start, even though it is set to 'Automatic'
b) even though the OracleServicedb_name service starts, I cannot connect to it
I don't have the registry entries that were cleaned as I was trying to press 'Cancel', and somehow the wrong button was pressed (yeah I know, I know....)
I am getting sonnection errors as follows:
When I try to connect using sql*plus, I get 12154: The listener does not currently know of the service in the connect descriptor (typed from memory as I'm at home with different network connections etc and I can't reproduce it at the moment).
Listener.ora:
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = ETSCF)
(ORACLE_HOME = D:\oracle\product\10.2.0\db_1)
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.35)(PORT = 1521))
(excerpt from) tnsnames.ora:
ETSCF =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.35)(PORT = 1521))
(CONNECT_DATA =
(SERVICE_NAME = ETSCF)
sqlnet.ora:
# This file is actually generated by netca. But if customers choose to
# install "Software Only", this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.
SQLNET.AUTHENTICATION_SERVICES= ()
I would really appreciate any help....
Thanks,
Bruce

Answer 1

Thanks - I have stopped and removed the listener, and set the authentication_services to NONE.
I can run a tnsping which can 'see' the instance using the sqlnet.ora file and the TNSNAMES adapter, but the database will not start up.
Having read other threads, it seems likely that the service name in the spfileETSCF.ora cannot be read. If I connect as sysdba, I can get to the SQL prompt "Connected to an idle instance" but when I start the database I get errors complaining about the default block size.
I have resolved this now but am most grateful for people taking the time to read and reply.
I have removed the reference to the parameter file and inserted the minimal parameters into the initETSCF.ora, and was then able to connect as sysdba and mount and open the db.
Thanks again!