Your install disk has been corrupted, probably because you started the installer in beginner mode without write protecting the disk.
Normally there *is* a startup-sequence on the disk. But it has been deleted by the attempt to upgrade the OS verison on the disk. Beginner mode by default tries to install onto the install disk, which is nonsense of course and deadly, too.
Never run the installer in beginner mode. And never remove the write protection from original floppy disks.
