You cant put another D: drive in your PC as each drive has to have a unique letter assigned to it. I assume what you meant was How to I put another CD drive into my PC, as most off the shelf PCs have the set-up A: - floppy drive, B: - second floppy drive (usually not present) C: - harddrive, D: - CD-ROM. Any drives that are added after this are automaticly assigned the next available letter in the alphabet.
Do you want to know how to physicly add another CD-ROM or how to add another harddrive?
Steven Graham, April 2006