If you are connected to the Internet, you can use LiveUpdate to get new virus definitions automatically when they become available. Updated virus definitions files are made available from Symantec Corporation, and can also be downloaded from many computer bulletin boards, electronically transferred from Symantec's FTP or World Wide Web sites, or mailed to you directly from Symantec Corporation. To find out how to set Live Update to run automatically see Steps to virus protection . Boot viruses - Viruses that can infect boot records or master boot records on disks. When your computer starts, it runs specific boot record programs to ready itself for work.
Data disks can contain boot viruses too.
A virus activates when your computer attempts to start from the infected disk. A virus can activate even if your computer can t start up from the infected disk. All boot viruses remain active in memory while your computer is on. While in memory, they continue to spread by infecting floppy disks accessed by your computer. Make periodic backups of your hard disk.