Personally speaking, I was always curious to know the technology behind a computer restart. Anyone can understand the process behind computer shutdown since we are habituated with the same kind of processes with our television sets, home theaters etc. But how do computers restart since it first closes down all running applications and gets shutdown, which means the power to the motherboard gets disconnected. Then how come it manages to restart the whole computing process from the beginning?
Well, the answer is not that much confusing at all. When we shutdownour system (by pressing the power button or from the OS menu), our computer starts saving all data and then it starts dumping all RAM (Random Access Memory). Once the RAM gets dumped completely, SMPS cuts off power to the motherboard and that’s how a computer shuts down.
Now when we click the “Restart” button on our computer, the operating system starts shutting down all active and running programs to make the RAM free. Once the OS regains all RAM resources, it will issue a command to the CPU to warm boot where BIOS system takes over and controls the whole booting process. In this process, BIOS loads first 512 bytes of detected boot device, jumps to boot loader code and restarts the computer.
Few might have the misconception that shutdown process is safer while system restart might harm the computer. Well, if you have read the above explanation, you can conclude with the fact the computer restart makes our job more easier.