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What exactly is booting process??

We have heard about booting process from our brilliant friends, teachers or from random youtube videos. If you ever have been amazed about what exactly is booting process then this is the collection of  basic information about it.

It is a process that initiate right after we press the power button until your desktop get available on your monitor. All the process happening during this interval is regarded as booting process. Booting is the process of starting a computer. When we press start button then at that time computer’s CPU doesn’t have any software in the main memory. So there must be some process that must load software into memory. And it has some steps to be executed.

 

In this booting process, initially the diagnostic testing sequence i.e. POST(Power On Self Test) tests that all the device connected on the computer are on proper working condition or not. If they are not on proper working condition then error message will be displayed in the desktop. This process is possible due to collective effort of microprocessor, BIOS(Basic input output system) located inside motherboard and RAM. If all these three devices are in proper working condition with no issue then POST process get executed. To confirm the execution of POST, keyboard indicator and mouse blinks.

After that BIOS search the booting devices to verify availability of operating system so that the computer gets booted. If booting device is found then the BIOS load it to the RAM. Booting devices means all external devices like hard drive, CD-ROM, pendrive etc.

BIOS consists of different files in order to execute its operations. In windows, BIOS loads three files just after computer is turned on. These files are Command.com, MS-DOS.sys, IO.sys. These all three files are compulsion to load the operating system on our computer. So after that process we get a prompt of user login/signup etc. Similarly for Mac, linux and other operating system have their own files.

Let us assume we have previously installed corrupted operating system. Then, if we want to install another operating system then at this scenario BIOS asks user either to repair corrupted operating system or may have fresh installation from bootable devices. We can also  delete the previous one.

So after the execution of all process without any issue we will be directed to  our desktop screen. So every time we press our power button booting process gets executed. From next time whenever you start your computer do think once about the boot process and analyze it.