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?
The ORA 12638 implicates that "Credential retrieval failed" -
The authentication service failed to retrieve the credentials of a User.
It seems that you have a problem with your administrator rights in the specific machine.
Regarding the other question,
Oracle installation creates a group (local in windows NT), which its members can login into oracle without the need of a password.
It seems that the Administrator Account has some problems with security issues.
My advice - try installing windows 2000 from the begining.
If you are using Directory services consult you Sys Admin.