Final answer:
The configuration is called 'dual-boot' and it allows the user to choose between two or more operating systems.
Step-by-step explanation:
The configuration called when a computer has two or more operating systems from which the user can choose is dual-boot. Dual-boot allows the user to select the desired operating system when the computer starts up. For example, a computer could have both Windows and Linux installed, and the user can choose which one to boot into each time the computer is turned on.