1. In an operating system, a means of running more than one program at a time. In preemptive multitasking, the operating system decides which application should receive the processor's attention. In contrast to cooperative multitasking, in which a busy application could monopolize the computer for as much as several minutes, a computer with a preemptive multitasking system seems much more responsive to user commands. Microsoft Windows 95 employs preemptive applications for 32-bit applications, but not for 16-bit applications. From QUECID