I have a barcode scanner works as HID device. Everytime a barcode scans it goes directly to windows keyboard, for example if I open notepad I can see the barcode typed there. As far as I know programmatically is it possible to to read HID data from your HID devices. But what happens if the user is already on a form with a text edit control? The scanned code will go inside the text box. Can you block incoming text and make a background-only processing? Can you explain the theory please?