Hello William, thanks for posting this in our community.
This is a common behavior in Excel because all open workbooks share the same Excel application instance. When you open a file from File Explorer, Excel brings the entire application window to the foreground, including all minimized workbooks. Unfortunately, this is by design, but there is a way to work around it.
You can use separate Excel instances if you want each workbook to behave independently. To do this, open Excel manually instead of from File Explorer, go to File > Options > Advanced, scroll to the General section, and check the option that says “Ignore other applications that use Dynamic Data Exchange (DDE).” Click OK to save the setting. After this change, when you double-click an Excel file in File Explorer, it will open in a new Excel instance instead of the existing one.
The advantage of this approach is that each window is independent, so minimized windows stay minimized. The downside is that it uses more memory, and cross-workbook links may not update automatically.
Kind regards,
John Oli