It's been a while since I used BT, and I need some advice..

I am trying to install BT on multi-HD system: Win 7 is installed on 500GB HD, and I want to install BT on 250GB HD - I got this part covered.

I do not want to install GRUB on my HD's, as I don't want to alter my MBR (I don't want to see GRUB selection menu every time I start my PC). I simply want to select which HD to boot from from BIOS.

So I installed BT onto my 250GB HD without grub. When I rebooted my system and selected to boot from 250GB HD, it's telling me "No OS Found" or other similar message, can't recall.

Does this mean that I have to install GRUB on my MBR?