If you’ve ever called Small Dog or Apple for technical support because your Mac wouldn’t boot, odds are it was suggested that you attempt a reinstallation of your operating system from the disks that came with your computer. The problem here is that if the reinstallation fails for whatever reason, there is no apparent way to eject the disk if the computer doesn’t start up.
A huge percentage of computers entering our service facilities have disks “stuck” in the drive when they’re checked in. To eject a disk, simply press and hold your mouse or trackpad button immediately after powering on your machine. Once the disk ejects, you can let go, and press and hold the power button for about ten seconds to force your computer to turn off.
Alas, this tip works only with a wired mouse. No bluetooth or similar wireless mouse will work unfortunately. If you have a wired keyboard but wireless mouse, there is another way: use the boot manager.
The boot manager is a screen summoned by pressing and hold the Option key on your keyboard immediately after pressing the power button. After a few moments, a screen will come up showing you the available startup disks. Once this screen appears, wait about ten seconds and then press the eject key on your keyboard to eject the disk.
Your mileage may vary on this one. Note that a drive that makes the usual ejecting noises but fails to eject a disk will require removal of the drive itself to save the disk. Failure to eject and inability to eject are two completely separate issues!