Just installed Oracle ORACLE CLIENT 10.2.0.4 Client on a Windows 2003 server. Trying to conect to Oracle database through SQL plus and get the error: ORA-12454: connect failed because target host or object does not exist. TNSPING unsucessful also. Replicated same install procedures on a Windows XP computer and could sucessfully connect. Used same SQLNET.ORA and TNSNAMES.ORA on both server and desktop PC to verify both files are valid.