Boot sector virus

Computer virus that infects the first or first few sectors of a computer hard drive or diskette drive allowing the virus to activate as the drive or diskette boots.

Tip: To help protect the boot sector from becoming infected with a boot sector virus many BIOS manufacturers have protection that can be enabled or disabled through the CMOS setup. This feature has to be disabled when installing an operating system such as Microsoft Windows that need to write to the boot sector during the install.

Also see: Boot sector, MBR, Security terms, Virus