a common installation recommendation!

Most computer systems today have two IDE busses that allow two devices each.

If you only have one CD-ROM and one Hard Drive, it is recommended that you install the HD on the Primary IDE as the Master and the CD-ROM on the Secondary IDE as the Master.

If you install additional Hard Drives or CD drives, keep the Hard drives on the same IDE bus, and likewise with the CD-ROM's.

If your system has two Hard Drives and two CD-ROM's,

you would have HD1 in the Primary Master position, HD2 in the Primary Slave position,

CD1 [Writer] in Secondary Master and CD2 [DVD] in the Secondary Slave position.