I have an old Pentium III HP that has 35 HD space now. I'd like to gut it and turn it in to a huge hard Drive, but is this even possible? I was thinking other wise to just go and buy a PC case that can support a Terabyte or so, but I didn't know what else I would need in that computer if I built one myself? Does it require an operating system? I can afford an external Terabyte Hard drive, but If i could use a computer as an external enclosure for internal hard drives I might have a better chance of not breaking the bank. Or is there the possibility of an external enclosure that holds multiple drives?