Can boot sector viruses infect non-bootable floppy disks?
Any diskette that has been properly formatted contains an executable program in the boot sector. If the diskette is not “bootable,” all that boot sector does is print a message like “Non-system disk or disk error; replace and strike any key when ready”, but it’s still executable and still vulnerable to infection. If you accidentally turn your machine on with a “non-bootable” diskette in the drive, and see that message, it means that any boot virus that may have been on that diskette *has* run, and has had the chance to infect your hard drive, or whatever. So when thinking about viruses, the word “bootable” (or “non-bootable”) is really misleading. All formatted diskettes are capable of carrying a virus.
