My neighbor let me borrow his sata harddrive. Will this process be easier and work with 3 harddrives? 1 harddrive with Windows 7, the other with Snow Leopard and the other with Lion.

Something is not getting along with Snow Leopard now, it refuses to even install Snow Leopard now that I have 3 harddrives... Don't know why. I think my Windows 7 side is to blame. Im backing stuff up and going to run quick-erase in DBAN so all 3 harddrives get a fresh clean so I can start over again. Probably the millionth time I have had to reinstall Windows 7.