Grub confusion

[Rashkae]

I'm going to assume these drives are formated with MSDOS partitions (and 
not GDR)

The pertinent info can be found on this handy wiki:

https://wiki.archlinux.org/index.php/Master_Boot_Record

The moneyshot is: dd if=/dev/zero of=/dev/sda bs=446 count=1


However, I think it would be best to familiarize yourself with your BIOS 
and find out where you specify either the boot drive or the HDD order.