Not exactly sure what you are saying but if you want to add a second HD to a desktop computer, then yes you can. Just set your current hd as a master and use the same cable for the second hd and use it as a slave.
If using an old hard drive I would suggest using a different IDE port for it. If you use the same port as your master drive you risk slowing down the fast hard drive. I know this is supposed to be no longer a problem with new computers but I still don't trust it
Ok I have an old HP vectra xu 5/133c computer. I was wondering if I could take the hard drive out of that and use it as a secondary HD in my Compaq presario 7360 without any problems?