I just removed the write protect on my SD file by manually pushing the gray lock switch to unlock. I am not sure what is in your F drive but it may a manual lock switch.
CD-ROM stands for Compact Disk Read Only Memory. By definition, you can only write to the disc one (a process often called "burning" the disc). Now, this is inconvenient in that the disc can't be...
The old 5.25 inch disks had a notch that is covered/uncoverd for write protection. The not so floppy 3.5 inch disks have a little plastic slide that did the same thing. Software disks in that format...