Several types of disks can be unmounted, including external hard drives, USB flash drives, iPods, flash memory cards, and disk images. In order to unmount a disk in Windows, open "My Computer," select the disk, and click the "Eject this disk" option in the left sidebar. In Mac OS X, select the disk on the desktop and either drag the disk to the trash (which changes to an Eject icon), or select "File→Eject" from the Finder's menu bar. Once a removable disk has been unmounted, it can safely be disconnected from the computer.