On Windows 2000, I have not been able to get the TNSListener to start after installation. I've checked the Listener.ora, TNSNames.ora and they look fine. After uninstalling Oracle 8i, I noticed that registry keys still exists in the registry. Also, notices registry keys from a previous Oracle Installation, I cannot delete the keys and I think this may be preventing the TNSListener service from starting.
Usually I get the error ORA-12541: TNS:no listener and I can't start the listener service.
Sample registry keys:
note: after I install 8.1.6 there is also a LEGACY_ORACLEORAHOME816TNSLISTENER