Can you see any contents on the pc, or do the contents appear scrambled? If scrambled the most common cause is the KN2000 had a DD disk drive so needed feeding 720K floppies. It can use HD, 1.4M, floppies, but these will not then read on modern equipment. If you only have HD disks, format them on the KN2000 and save your files. Tape over the floppy ID hole (not the write protect switch hole, the other side) and try again.