ORA-12645: Parameter does not exist.
Cause: A sqlnet.ora parameter from which a value was needed does not exist.
Action: Set the parameter in the parameter file.
Check that the following file is present: C:\Program Files\ora92\network\Admin\sqlnet.ora.
Note, sqlnet0.ora may also be present.
If sqlnet.ora file is not present, re-running the Oracle client installer, from http://web.mit.edu/software/win.html will replace it.
If sqlnet.ora is present, compare that file with sqlnet.ora from known working machine.