Virtual Machine CD/DVD-ROM drive can be connected to a real CD/DVD-ROM drive of your computer as well as to CD/DVD .iso image. To get information on using CD/DVD images in Parallels Workstation look in CD/DVD Real Discs and Images topic.
The current version of the Parallels Workstation allows up to four IDE devices (hard disks and CD/DVD-ROM drives) to be connected to a Virtual Machine. This means, that there can be no more than four hard drives plus CD/DVD-ROM drives, i.e., it doesn't matter how many IDE devices will be hard drives and how many will be CD/DVD-ROMs.

Device Status:
If you wish to temporary disable a CD/DVD-ROM drive without deleting it from configuration, deselect Enabled checkbox.
Note: If you start the operating system with the CD/DVD-ROM drive disabled, you cannot change this option when Virtual Machine is running.
If the CD-DVD-ROM drive is enabled, it can be connected/disconnected while VM is running. Media that CD/DVD-ROM drive access can be changed also.
If CD/DVD-ROM drive is enabled, you can select Connect at startup checkbox to start the guest OS with CD/DVD disc inserted.
Emulation:
If you have a physical CD/DVD-ROM on your computer, you can use it in the Virtual Machine. In this case, select Use real CD/DVD-ROM checkbox, the name of the physical CD/DVD-ROM (for example, D:) will be shown in the CD/DVD-ROM drives drop-down menu and available for selecting.
Note: In Linux primary OS to be able to connect Virtual Machine CD/DVD-ROM drive to a real CD/DVD-ROM drive, you should have system privileges to access real device. Otherwise real CD/DVD-ROM drive will not appear in the list of available devices despite it is installed on your computer.
If you want to use CD/DVD image (e.g., the .iso file), select Use image file flag. As you select it, another field where you can enter the CD/DVD image file name appears below. Specify the path to your CD/DVD image file or click the Browse button and locate the CD/DVD image file.
Attachment Options:
Choose IDE slot to connect to CD/DVD-ROM image in the Connect to list. If you want the CD/DVD-ROM to be startup drive select IDE 0:1 in the list.
Note that if you set two startup drives at once - hard disk (IDE 0:0) and CD/DVD-ROM (IDE 0:1) - guest OS will try to boot according to sequence set on the Booting Options tab of the General Options.