Hi Drew. I'm Greg, awarded MVP for eleven years, Volunteer Moderator, and Independent Advisor here to help you until this is resolved.
If you're using WIndows backup then it should be in a folder named Windows Image Backup and not tampered with at all. Recover as shown here:
https://www.howtogeek.com/239312/how-to-restore...
If it will not be detected on the external you can try moving it to another attached drive if you have one to see if it sees it there. You can also try browsing into the image from Disk Mgmt to extract any files you need: https://www.tenforums.com/tutorials/61391-vhd-v...
Windows imaging is no longer supported nor is it recommended by any expert anywhere. The unanimous choice of experts is free Macrium which is fully flexible, easy to use and just works:
https://www.howtogeek.com/howto/7363/macrium-re...
I hope this helps. Feel free to ask back any questions and keep me posted. If you'll wait to rate whether my post resolved your problem, I will keep working with you until it's resolved.
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