Of course, this is a favourite thing for
boot sector viruses to print out on loading. The user
obligingly removes the floppy disk, presses
any key, and the virus writes itself to the hard drive.
Well done.
Relly nasty viruses will keep a copy of the original boot sector, so if there is something in it that absolutely has to load (one of those nasty 'let a 486 access large hard disks' programs, for instance), you then won't be able to access the drive without loading the virus.
catch-22.
Best way to protect against these viruses is to set the bios to boot off the
hard disk first, and only set it to boot off the floppy when you need to. If you forget, and see this message,
hard reboot. Don't press any key, and don't
control-alt-delete, as quite a few can survive a
soft reboot.
It's a good thing
preemptive multitasking and lack of real
dos modes make
windows 9x,
linux, etc. incompatible with most viruses ability to
TSR, so they don't spread as well as they used to... They tend to only be able to spread from the infected floppy to the hard disk, and to any floppies inserted before the hard disk is booted. They (generally) can't stay in memory and infect every floppy disk put in the machine anymore. With use of floppy disks declining, these viruses are becoming less and less of an issue.
Which is a
Good Thing.