Which of the following operating systems used non-preemptive scheduling for…

Concept

Preemptive scheduling allows the operating-system kernel to interrupt a running task and give the processor to another runnable task. The task does not have to surrender the processor voluntarily.

In non-preemptive, or cooperative, multitasking, a running application keeps control until it yields, blocks, or finishes. Therefore, one application that does not yield can delay other applications.

Application

Windows 3.1 used cooperative multitasking among Windows applications. Each application processed messages and was expected to return control so that another application could run.

Contrast

• Unix uses kernel-managed preemptive time-sharing among runnable processes.

• Linux uses a preemptive kernel scheduler for runnable tasks.

• Windows NT schedules runnable threads preemptively through its kernel dispatcher.

Cross-check

If a Windows 3.1 application stopped yielding control, other Windows applications could appear frozen. That behaviour follows the cooperative model and distinguishes it from kernel-enforced preemption.

Result

Therefore, the operating system described is Microsoft Windows 3.1.