If you are an old computer user then you might think windows operating system with its pentium 4 processor is the very first computer and operating system to multi-task... Right? Well actually you're wrong. You see before windows with its pentium 4 processor existed there's another computer and operating system that can actually multi-task. The very first commercially successful computer that uses preemptive multitasking is the Commodore amiga 1000. Commodore amiga 1000 was the ancestor of multimedia computer and considered way ahead of its time because the OS itself was 32 bit running on a 16-Bit hardware accelerated computer. The os it's called workbench/amigaos