10g Database Configuration Assistant fails with code ORA-12546

I originally thought the problem related only to the install process of 10g 10.1.0.2 on Windows Server 2003 but I have now established that the DBCA will not run successfully when run on its own either. I can get all the way through the wizard and then when I click OK to start the database creation it brings up a window with a tick beside "Copying database files" and the item being "Clone database creation in progress". At this point it fails with error:

ORA-12546: TNS: Permission denied.

So I can't create any databases - serious problem! What could be causing this? I am a local administrator and there aren't any special file or directory permissions anywhere on the server. It's basically a fresh install of Windows Server 2003 with the only other program installed being Sybase Adaptive Server Enterprise 12.5.3 (please don't ask me to uninstall this). The firewall is not on.

It has been suggested that it might be a clash of ports for the listener but it doesn't look as though it even gets to install listeners. Even so, how do I know which port the listener (if any) is trying to use?

It's a mess and it is a very serious problem. Any suggestions or assistance would be greatly appreciated.

Thanks,

Wes Received on Wed Jul 27 2005 - 23:59:04 CDT