I have met questions in installing ORACLE8.1.6 on Window2000. When I finished the installation of Window2000,then I installed ORACLE8.1.6. I login as Administrator and install Oracle.But When the installation proceed half,the error occur: ORA-12638. The installation is faild. I think user's privilege may be insufficient .So I login as another user with Administrator privilege.But the error is still exist. Why? The question is strange. Because I have finished the ORACLE installation on Window2000 on another Server which environment is same as the last one.

Another question is when I install Oracle as Administrator,the installing program ask me the Password for INTERNAL.But when I install Oracle as general user with Administrator privelge,it does not ask me any password. Why?

Any help is highly appreciated.
Thanks