Thanks for the replies, Lightning & dbminter. I guess it's obvious I don't know what I'm doing!
I'm not sure what type of video file I ended up with, to be honest. I can tell you it doesn't have a folder with VIDEO_TS, etc, in it. It's a single file that Windows Explorer describes as a "video file."
I have two DVDs that work in my daughter's DVD player, and these DVDs contain VIDEO_TS folders with IFO/VOB/BUP files in them, as well as an AUDIO-TS folder which is empty.
I think you are correct in your advice to convert my AVI file to DVD video files with the VIDEO_TS folder, etc. I will download DVD Flick and try that. Will this software burn the DVD with the appropriate folders, etc? Or do I use ImgBurn for this?
In terms of what I was "following carefully," I used ImgBurn's "Create image file from files/folders" feature to create the ISO image from the AVI file. Then, I used ImgBurn's "Write image file to disc" feature. I take it, this is not the correct process to create the DVD that will work. I will try DVD Flick.
Thanks again!