Hi Gilles22740 and welcome to the HP forums!!
I see you are working with a Photosmart C7280 and Windows 8.1, but they don't always seem to be working with one another. I will certainly do my best to assist you with this!
Are you saying that the main issue is with the OCR software? You're trying to scan as editable text and it's not working?
I will recommend that you start with running the HP Print and Scan Doctor as it can often find and solve issues on it's own, or at least offer suggestions if it's able to detect an issue.
Hope to hear back from you soon!