My Booki not recognized by BIOS

My Book 3TB is being used as a simple external hard drive.  It shows up in Win8 and I’m able to use it.  However, it does not show up in the BIOS which means I cannot use it for a system backup.  Or use it to boot my computer.  Is there a way to fix this?

Check if there’s any Bios updates

system backups can be done with Win Backup utility

BIOS up to date.  When installed on Win7, 3 drivers were installed.  Same thing did not happen in Win8.