ITHELPDESK

Boot Sequences of the Operating System When we press the power button, If there is proper voltage, a short is created and send a pulse command to PSU (Power supply unit) to give power to all the devices and to send reset signals to the processor(CPU).                                                                                                                                                                                           CPU has the instruction pointer pointing to the reset vector within the system ROM and the CPU starts executing the small firmware or Jump instruction to load the BIOS.                                                                                    BIOS  initialize the primary graphics through video BIOS code and also the other secondary devices. BIOS starts the POST (Power ON Self Test) process which will  run the basic test for the devices and sets the device to it's default values. If there is any error during POST, beep codes and light co