It's been years since I booted a windows OS on real hardware, but from what I can remember, windows likes to take over your drive for booting purposes. With that said, I would suggest the same thing that has already been suggested here. Remove the drive that holds your Linux installs, and leave only the drive that will hold windows plugged in (you dont even need to change the jumpers... just unplug the primary master would be ok...unplug its power too). Then install windows as you normally would. When that's done, plug your linux drive back on, and and machine will boot Linux.
Configure your bootloader (use vliloconf if on Vector) and you will be able to boot either or.