"insifficient priviliges..."

makes me think your password file is missing or is not at the correct location. For Windows it should be in --

Oracle_Home\database folder and should be named as pwdSID.ora

Then try connecting as sys with the password you specified at the time of password file creation.

I am assuming that you are connecting from the database server itself (not the client)

You should be part of the ORA_DBA group in Windows NT if you wish to connect as sysdba without the password --

connect / as sysdba

For Remote authentication you will also need to set the --

sqlnet.authentication_services = (NTS)

in the sqlnet.ora on both client and server side

- Rajeev