A boot sector of the hard disk is a favorite place of various viruses. Here they can start virus infection of the rest part of the hard disk and other media connected to this computer. To prevent an authorized entering a boot sector of the hard disk, there is a special parameter in BIOS that locks any attempts of writing. And locking is done for all types of writing – no filters are placed here. That’s why, if you install Windows, utilities by Norton or any other program, this part of the hard disk should be opened for writing.
For anti-virus locking at BIOS level, use the parameter “Boot Sector Virus Protection” (Virus Warning, Anti-Virus Protection) which is located in a section “Standard CMOS Futures” (Advanced CMOS Futures). If a value “Disable” is set for this parameter, it means that it is off and writing in the boot sector is allowed. If this parameter has a value “Enable”, the boot sector is locked and there can be difficulties with the installation of new program products.
In general, locking of the boot sector of the hard disk is an anachronism which nowadays can be easily replaced by any anti-virus program. Such program does not protect the boot sector from writing but checks its contest for viruses.