"Check your sqlnet.ora. I faced a similar issue when SQLNET.AUTHENTICATION_SERVICES= (NTS). Change this to SQLNET.AUTHENTICATION_SERVICES= (NONE) and create your database afresh. It will succeed."

I actually found this doing searches on other msg boards and tried it, and it resolved the original ORA-12638 error, but it led to a host of additional error messages as the installation finished.

So, despite these error messages, I finished the installation of Oracle10g on XP Pro and created a database called cassure. When I attempt to logon with system/manager1@cassure, I get the following error msg: ORA-12500: TNS:listener failed to start a dedicated server process.

Here is my listener.ora file:

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME = PLSExtProc)
(ORACLE_HOME = C:\oracle\product\10.1.0\Db_4)
(PROGRAM = extproc)
)
(SID_DESC =
(ORACLE_HOME = C:\oracle\product\10.1.0\Db_4)
(SID_NAME = orcl101)
)
)

LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
)
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = alanv)(PORT = 1521))
)
)
)

All paths are correct. When I try to start the listener in command prompt, I get the following messages:

TNS-12560: TNSrotocol adapter error
TNS-00530: protocol adapter error
32-bit windows error: 1056: unknown error

I've also tried to launch Enterprise Mgr and logon to this database, but am getting vague error messages (no ORA or TNS numbers).

This is my sqlnet.ora file:

# sqlnet.ora Network Configuration File: C:\oracle\product\10.1.0\Db_4\network\admin\sqlnet.ora
# Generated by Oracle configuration tools.
SQLNET.AUTHENTICATION_SERVICES= (NONE)
NAMES.DIRECTORY_PATH= (TNSNAMES, EZCONNECT)

This is my tnsnames.ora file:

# tnsnames.ora Network Configuration File: C:\oracle\_products_\10.1.0\Db_4\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

CASSURE =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = Alanv)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = cassure)
)
)

ORCL101 =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = Alanv)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcl101)
)
)

EXTPROC_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC))
)
(CONNECT_DATA =
(SID = PLSExtProc)
(PRESENTATION = RO)
)
)