Problems connecting to remote Oracle DB on windows using active record

I am trying to connect to an older oracle DB remotely, I think version
8 or 9. I downloaded the instant client stuff from oracle and copied
oci.dll and oraociei10.dll to my windows/system folder (windows XP) I
get the error.

C:\rb-play>ar_connect_ss.rb
env.c:257:in oci8lib.so: ORA-12514: TNS:listener does not currently
know of serv
ice requested in connect descriptor (OCIError)
        from c:/ruby/lib/ruby/site_ruby/1.8/oci8.rb:228:in
`initialize'
        from c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/
active_recor
d/connection_adapters/oracle_adapter.rb:585:in `new'
        from c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/
active_rec

If I change the adapter to 'oracle' I get

C:\rb-play>ar_connect_ss.rb
env.c:257:in oci8lib.so: ORA-12154: TNS:could not resolve the connect
identifier
specified (OCIError)
        from c:/ruby/lib/ruby/site_ruby/1.8/oci8.rb:228:in
`initialize'
        from c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/
active_recor
d/connection_adapters/oracle_adapter.rb:585:in `new'
        from c:/ruby/lib/ruby/gems/1.8/gems/activerecord-1.15.5/lib/
active_recor
d/connection_adapters/oracle_adapter.rb:585:in `new_connection'

I've done a bunch of google searches on this. I read if I am using
instant client I don't need a tnsnames.ora file, which I'm not that
familiar with that file anyway.

Any ideas on this let me know, it has not been as easy as I've hoped
for this.