Every time I attempt to open a file on my floppy A: drive I get the following messages, " A:\ is not accessible", and " The system cannot read from the specified drive." I changed the disk to a new one. I save a file to it and opened it--all was fine. When I rebooted the computer and attempted to open the file again from the disk, I received the messages listed above. Is it a VIRUS? What should I do next?