I have a Dell with windows XP Pro V2002. I want to take the HD out of my old Windows 95 machine and use it for a backup drive in the Dell. I also want to keep all the info on the old drive.
First, check that there actually is room inside your Dell for another hard drive. If there isn't, then you have to get an USB enclosure and use your old drive as external storage.
Put the old drive on the same IDE cable as your CD-ROM. Set the jumpers on both devices so that one is "master" and the other "slave". You may have to get a new three-plug IDE cable in case Dell has decided to save ¢50 and build your computer with some short two-plug cables.