How do I use old desktop as second hard drive?

yes you can if you take the old HD out and set it to slave

to set it to slave look at the sticker on your hard drive there will be a section for the jumper

to locate the jumper look at the drive with the connections facing you. youll see 3 sections with pins one section will be very small with a little plastic piece over 2 pins thats the jumper. move it to the slave position.

now you can open your new pc and connect this hard drive to the same IDE cable (the flat wide cable) that the other HD is on.

now you can boot up and it should show up as a drive in my computer. if it doesnt you may have to set the jumper of the other item attached to the same IDE cable as the one you just added the HD to. there are 2 different master settings one is master and one is master w/ slave some equipment is more picky than others. just look at the sticker and it will tell where to put the jumper.good luck

You would take out the hard drive from the old Gateway machine and install it inside the new eMachine desktop.

Look at the pages 5-10 here for the step-by-step graphical instructions on how to do it.

http://www.maxtor.com/en/documentation/installatio...

If you know how to do it, you can do it in 10 minutes. Take care when attaching the cables to the pins. You do not want to bend them.

You can buy a usb to usb cable or you can take the hard drive out and slave it into your computer. Just make sure that the jumpers on both drives are set correctly.