How can I get my sewing machine to see Windows 8.1?

Episode 1084
Gary fromGary just upgraded to Windows 8.1 and he uses it to control his CnC machine for milling. He can write the data to the floppy, but the machine can only read the header and nothing else. Leo says that it could be that the upgrade broke the connectivity between the two and Windows 8.1 isn't compatible.