Welcome to the Community, marc.
Let me lend a hand and share with you some information about barcode scanning in QuickBooks Desktop.
Before you install a new scanner, you will first need to check if the MC40 scanner uses a TWAIN-compliant scanner with QuickBooks Scan Manager. The formats below are the specifications that need to be met to ensure your scanner will work QuickBooks.
The Barcode Scanner Tester App will check to see if QuickBooks Desktop will recognize your scanner.
These recommended articles are a good reference:
As always, you can reach out to our customer care agents if you'd like someone to be with you as you go through these steps. They can pull up your account in a secure environment and assist you further.
You can always stay connected with me by leaving a reply below if you have additional questions about scanning barcode in QuickBooks Desktop. Have a good one.