If you have an external optical drive in OS X, the built-in Eject key on the keyboard may not work with it, so here are some options for handling external discs on your Mac. Topher, an avid Mac ...

Optical drive tray will not open. First, restart your Windows PC and see if it helps. I have found that a simple restart solves many problems, including this one.

Open Windows Explorer, right-click on the USB drive with it's uniquely assigned letter, and select Create shortcut. It'll appear on your desktop. Right-click it and select Properties.

Some PowerMac G5 Hitachi optical drives cannot boot from CDs or DVDs (#3): Related to keyboard connection ...

Optical drives let your computer read and interact with discs like CDs, DVDs, and Blu-rays. However, ... and feature an open/close button that controls access to the disc tray.