Thank you for your post.
The admin_console_init_webstart.jnlp file should have been placed in the folder:
Documents and Settings\Administrator\My Documents\Downloads
I'm not sure why your error is referenceing the Temporary Internet Files folder. On your second machine, you will see the file in the proper location.
Try uninstalling FileMaker Server, remove any references to admin_console_init_webstart.jnlp, and reinstall FileMaker Server. Go through the deployment and try again.