I don't dual anymore, but when I did I worked with the boot.ini, I believe. It has one entry per operating system. This includes which drive and which partition on the drive.

>Thanks Craig
>
>In my mind I had limited dual boot to operate only on partitions on the same HD as C:. Happy to learn differently.
>
>>I have two physical drives. You can also install on two partitions and dual boot that way.
>>
>>>2 separate drives or 2 separate partitons (on the same drive)?
>>>
>>>Does MS' boot manager work across multiple physical drives?