Computer Startup

Power Electricity Warms up components And heads to the CPU

BIOS Basic Input / Output System chip with it’s programs called. BIOS runs POST

CMOS The CMOS Chip contains the most fundamental information, like basic computer components setup and the date That is why it needs a battery CMOS: Complementary Metal Oxide Semiconductor

POST Power On Self Test You may hear some drives or other actions as your computer is being tested More than one beeps indicates a problem with the tested hardware In some BIOS two beeps is OK

POST Power On Self Test

POST BIOS compares memory records with the CPU to ensure they are running right

Bios Actions Load Device Drivers Load Interrupt Handlers For: Keyboard Mouse Hard Drive Floppy Drive Etc.

The System Timer is Checked To ensure proper pacing Above – the worlds most flexible clock

Check System Bus BIOS has CPU Check System Bus to ensure all components are functioning. From Webopedia.com: system bus The bus that connects the CPU to main memory on the motherboard. I/O buses, which connect the CPU with the systems other components, branch off of the system bus. The system bus is also called the frontside bus, memory bus, local bus, or host bus.

POST tests memory and video

Option to run BIOS F2 or DEL

Why? Some settings may need to be set Hard Drives You may need to change the boot order Hard Drive CD Write down key settings before changing them!

Cold Boot or Warm Boot The computer had stored a value in memory to indicate if the computer was simply restarted with a “warm boot”. Warm boot – BIOS is done. Cold boot – Continuing…

RAM Test All Ram Written and Read

(above are just some useful images of disks and connections) All Drives Tested (above are just some useful images of disks and connections)

Operating System Started This process is the Boot. BIOS Transfers control to the OS Can have multiple Operating Systems – Including more than one Windows Linux Etc OS is on the Hard Drive

Windows Starts Hardware Gets Recognized by Windows

Further Initialization Plug and Play Drivers for PCI (and ISA) Disk Drives fully initialized Video Drivers Loaded Services Added, such as disk defrag and partition

Logon

There you go!