Thank you for getting back to us here on the Community page, @sheldon211.

QuickBooks won't accept restoring files from the portable drive. For now, you can save a copy on the desktop and restore the file from there. Once done, you can save a copy of your company file to the portable drive.

I'm adding these screenshots as your visual references from the steps provided above to restore back up file in QuickBooks Desktop.

For additional references about restoring back up file, check out these links:

• Restore a backup of your company file
• Move your company files to another computer
• Fix backup company file issues in QuickBooks Desktop

Also, read the topics from our QBDT help articles in case you need guides while working with QuickBooks in the future.

Thanks for allowing me to help. I'm here to help if you have any other questions. Just add a comment below. Keep safe, @sheldon211!