Yes, if you want to put the old hard drive into the new computer then you need to take apart the old computer, disconnect the HDD and take apart the new computer and connect it into that. However that can lead to some issues like the computer not booting due to lack of drivers e.t.c. Or if you have 2 hard drives you can clone the old hard drive to the new one using software.http://www.makeuseof.com/tag/5-ways-to-clone-and-copy-your-hard-drive/ I now realized that my explanation didn't make as much sense as i though, sorry about that.