Configuration between 2 systems

[Ayman Altounji]

I have 2 identical Proliant 1600R systems, both with 221 array controllers. One is the hardware backup for the other. The main system has 2 4.3 Gb drives configured as a single logical drive. When I remove the 2 drives from the main system and try to boot the backup system with them, the controller recognizes the logical drives, but Windows will not boot. I understand that you can replace a controller with another controller in the same system (in the case of controller failure) with no loss of data, but can you change the whole computer? What are the supported conditions?
The reason that I do this is so that i can have a bootable system with the same installed programs and configuration in case the main server (or the whole server room) becomes unuseable.