MacBook Air (Mid 2013): Keyboard/trackpad inoperative, black screen, or alert messages when installing Windows 7

When installing Windows 7 using the Boot Camp Assistant on MacBook Air (Mid 2013) computers, the following issues might occur: The keyboard and trackpad are inoperative Black screen "Press any key to boot to CD or DVD" or "CDBOOT: Couldn't find BOOTMGR" alert messages "Setup was unable to create a new system partition or locate an existing system partition." This occurs when installing Windows 7 from DVD using an external USB optical drive.