Why not just shove the disk in the drive and see what happens?
He says he did, and Windows helpfully offered to format it for him.
Most "new" (say manufactured in the past two decades) 3.5 floppy drives don't support DD disks, anymore. AmmoJammo is correct. Look for an older floppy drive if you must read it on a PC.
CrossDOS on Amiga is probably the easiest solution for today, though.
