If you get a second internal harddrive, then later when you want to get a second computer you can use that second hardrive in it. When you go to buy the second computer, you can just buy an upgrade kit for a couple of hundred dollars instead of buying an entire computer. Most upgrade kits right now have everything including the case except for the CDROM and hard drive. You'll have the hard drive, all you have to do is get a CDROM.