BIOS protection of the Master Boot and System Boot Sectors.
Many BIOS versions offer partial virus protection of the Master
Boot Sector. This creates problems when an access
control product is installed that is designed to encrypt
the master boot sector (the partition table is created). The computer's BIOS
prohibits any writing to the Master Boot Sector, and so prevents the encryption
process. If you know you are using this BIOS function,
you must remember to disable it before installing an
access control product.
Windows Privacy Tools - http//www.privacywindows.com