It sounds like your disk is write-protected.
Floppy disks have a safeguard feature that helps users avoid copying over important files.
Files on a write-protected disk can be accessed, but you can't save new files to the disk. If you share disks, the write-protect feature is a good way to stop others from inadvertently storing information on your disk. While anyone can easily flip the write-protect tab, the action will at least cause him or her to think twice before doing so. To submit your own question or find an index to previous questions and answers, click here .