There are ways to get around that issue. i.e. "C" drive. My machine has three boot partitions. "C" drive lives in a "Hot Swap Tray", and if for any reason it becomes unuseable, I can replace it with a duplicate "C" drive that is also in a "Hot Swap Tray" that I keep sitting in reserve on a shelf. Further I also have a boot partition on "D" drive on one of my internal HDDs. That one was a lot of work to setup though, cause what I did was clone my "C" drive onto that partition, then with my "Hot Swap Tray" "C" drive installed, go into the bios and set that internal HDD as my boot partition, then boot from it, then use the Windows registry editor, to go through the entire registry, changing "C:\" to "D:\" and "C?\" to "D?\" one at a time, (about 16000 of them.) But setup that way, I can go into the bios and choose which HDD to boot from, - to boot from, - either "C" or "D".
Done that way, the machine will always boot from whichever HDD is set in the bios as being the "Primary Drive" without asking which partition you want to boot from.
NOTE : When you are editing the registry on "D" drive, to change the occurances of "C:\" to "D:\" the "C" drive must be available or else the machine will not boot from "D". But once you have finished the changes, the machine will boot from "D" even if the "C" drive is shut down, or removed from the machine.
I also have "Norton Ghost Images" of all three boot partitions, so in the event that one of them becomes unuseable, I can use one of the other boot partitions to restore the unuseable one from its "Ghost Image".
Edited by JHMcG, 15 June 2013 - 10:32 AM.