In spite of the fact that the Internet is one of the most common means by which viruses spread, floppy disks are still an important virus entry-point.

Apart from scanning all the floppy disks that you use, another way to avoid boot viruses is to remove all disks from the drives on shutting down or restarting your computer.

For times when you forget to do so, it is a good idea to have an antivirus program that checks for infected floppy disks.