High Sierra won't install older OS in a different drive

Thanks to both of you. I had tried Diskmaker before now, but ran into errors and problems. Whatever-this time it worked, that is, it installed the system onto the disc. What it didn't do, I noticed, was go through the usual process of requesting my name, email, password, language, etc. So now I have the right OS on the right disc, but I can't start up from it. Not sure what went wrong. Is there a workaround, or...well, is there a workaround?

Yes. That's what happens. I enter the password, there's a pause, and then the same screen comes back and I go through the same process again and again, ad nauseum. Clearly there was something wrong with the install. So I stopped wasting my time with Diskmaker and used Terminal, following a script I found online courtesy of MacWorld. It worked. I now have a functioning OS 10.10 disc. I've tried Diskmaker before, it's the first app anyone suggests, and I have never been able to get results with it.