I purchased an iMac in late 2013. This model has no disc drive. It came with Mountain Lion pre-installed. If I ever needed to perform a clean install of Mountain Lion, how can I? I don't have an installer file and no disc came with the computer. What's the official way to deal with the fact that I essentially don't own a copy of the OS my computer came with?
One is to use the build in recovery installed on your hard drive. To check for it use disk utility, but it is a hidden partition so make it non hidden first.
Second one is to use the Internet Recovery.
For clean install:
The OS X Recovery Disk Assistant lets you create OS X Recovery on an external drive that has all of the same capabilities as the built-in OS X Recovery: reinstall Lion or later, repair the disk using Disk Utility, restore from a Time Machine backup, or browse the web with Safari.
Note: In order to create an external OS X Recovery using the OS X Recovery Assistant, the Mac must have an existing Recovery HD.
To create an external OS X Recovery, download the OS X Recovery Disk Assistant application. Insert an external drive, launch the OS X Recovery Disk Assistant, select the drive where you would like to install, and follow the on screen instructions.