Hello, Gary L. Smith_2000.
We appreciate you posting in Microsoft community.
Benefiting from your detailed description, I noticed you have some questions about the Thumbs.db file in Windows.
I'm glad to have the opportunity to help you analyzing this.
Let’s start with some explanations:
Thumbs.db is a hidden file generated by the Windows operating system that is mainly used to store thumbnail caches of image files. Its main function is to speed up the preview of images in a folder, especially in folders containing a large number of images.
The Thumbs.db file is usually labeled as a “hidden” and “system” file. Even if you choose to show hidden and system files in Windows Settings, some programs (such as File Explorer and PowerShell) may still not show it.
When using a program such as Word, you may be able to programmatically access the contents of a folder and discover the existence of the Thumbs.db file. This is because Word uses an API that may list all files, including those marked as hidden or system files.
On the other hand, PowerShell and some other tools may follow different rules, causing them to fail to detect the Thumbs.db file.
You can refer to this article about how to remove it:
Should I delete an unknown thumbs data base file from my computer? - Microsoft Q&A
Feel free to let me know if I have not made it clear or you need more help.
Best Regards.
Jeffrey - MSFT | Microsoft Community Support Specialist