Which of the following is not a hardware device?

Microsoft Disk Operating System is an operating system that was created for IBM compatible computers. It is not used anymore but the Windows command line from it is still used. Storage devices are computer equipment for storing information.

Output devices receive data from a computer for projection or duplicating it, such as a monitor or printer. A CPU stands for the central processing unit and is sometimes referred to as the processor. A CPU is quite small and is used in phones, computer, and televisions. It can become hot while run and is often attached to a small fan.