HELP cloning system partition

What I want to do is make a copy of my system partition onto another hard drive and boot from it.

What I already can do is have two bootable partitions on my boot drive, and boot from either one. I cloned my second partition (my main Windows 2K runs on D, because C is 2 GB for DOS!) to the new drive, also second partition. Boot.ini correctly has it as multi(0)disk(0)rdisk(2)partition(2), the second partition on the third disk. Windows boots up partway, and then bluescreens with INACCESSIBLE_BOOT_DEVICE. I cloned it from my working system partition.

Can anyone tell me what I have to do to
1) Clone the second partition of my boot disk, which is my win2K partition, to another drive (I think that I have done this)

2) Modify boot.ini on the boot drive to complete the boot from the Windows installation on the second partition on that other drive

Why? Well, as I experiment with OS versions, I want to be able to use assorted drives and swap them easily - I'm using e-SATA! If I can boot from the eSATA drive, then I can keep a few drives around and swap them out as needed. The boot sector remains on the first disk, the active partition remains on the first disk, but the Windows directory resides on one of many possible locations.

And no, thank you, I don't want to use a boot manager.