[Question] What is the 1st thing the computer does when you turn it on

By Nickyyy
in Hardware Hangout

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Nickyyy

Posted
Posted (edited)

So today my ICT teacher asked me what is the 1st thing the pc does when you turn it on.

I said it checks all systems suck as ram gpu etc and then Posts, then loads the BIOS and then boots the OS.

She Said I was wrong and it loads the OS first. I argued with her a little feeling I was right but then she got mad @ me and told me that she knows best and she is the one with the degree, don't get me wrong shes a lovely person and a great teacher but I just feel that I was right.

So thats why I am here, please tell me what the Pc does when you first turn it on, I'm posting here as this community is full of experts and I feel I can show her this with a smug look on my face :) lol

Edited by kerno
Grand Master

Hell-In-A-Handbasket

Posted
Posted (edited)

it wouldnt be called POST if it didnt POWER ON SELF TEST

to quote Boot Sequence

1. First is the POST, this stands for Power On Self Test, for the computer. This process tests memory as well as a number of other subsystems. You can usually monitor this as it runs each test. After that is complete the system will run POST for any device that has a BIOS (Basic Input-Output System). An AGP has its own BIOS, as do some network cards and various other devices.

2. Once the POST is complete and the BIOS is sure that everything is working properly, the BIOS will then attempt to read the MBR (Master Boot Record). This is the first sector of the first hard drive (called the Master or HD0). When the MBR takes over it means that Windows is now in control.

3. The MBR looks at the BOOT SECTOR (the first sector of the active partition). That is where NTLDR is located, NTLDR is the BOOT LOADER for Windows XP. NTLDR will allow memory addressing, initiate the file system, read the boot.ini and load the boot menu. NTLDR has to be in the root of the active partition as do NTDETECT.COM, BOOT.INI, BOOTSECT.DOS (for multi-OS booting) and NTBOOTDD.SYS (if you have SCSI adapters)

4. Once XP is selected from the Boot Menu, NTLDR will run NTDETECT.COM, BOOT.INI and BOOTSECT.DOS to get the proper OS selected and loaded. The system starts in 16-bit real mode and then moves into 32-bit protected mode.

5. NTLDR will then load NTOSKRNL.EXE and HAL.DLL. Effectively, these two files are windows XP. They must be located in %SystemRoot%System32.

6. NTLDR reads the registry, chooses a hardware profile and authorizes device drivers, in that exact order.

7. At this point NTOSKRNL.EXE takes over. It starts WINLOGON.EXE that in turn starts LSASS.EXE, this is the program that display the Logon screen so that you can logon

Edited by Hell-In-A-Handbasket
Grand Master

markwolfe Veteran

Posted
  • Veteran
Posted
The first thing it does is POST, so you're right-er, even though checking hardware and POSTing and mostly the same.

However...I wouldn't consider a forum where random people answer to be credible. ;)

Agreed. Instead of showing her a forum with miscellaneous people posting, how about a little technical research of your own? ;)

Enthusiast

Nickyyy

Posted
  • Author
Posted
Yeah what did she say happens?

And I hate teachers like that, think they know it all when in reality you wouldnt let them loose on a speak and spell

She said the OS posts first, then I asked her about the white scrolling text, isn't it the BIOS loading 1st? She said no it was a part of the OS or something I can't remember exactly but I think she said it was a part of the OS. Completely false as its stored on the Mobo, but thats what irritated me. I knew she was right but she always tells me to be quiet, and if I argued on she would of probably sent me out or something lol.

But yeah and to as why I asked this forum I think a human response would be better than one source from the internet as it could easily be proven to be false.

Experienced

C_Guy

Posted
Posted

Ask her how the computer knows WHERE to load the operating system from if it hasn't checked the BIOS yet. And how can it check the BIOS if it hasn't POST'd yet?

But don't argue with her. Apparently her degree doesn't mean much if she doesn't even know how a computer starts up. Let her be happy in her ignorance.

Grand Master

+shift. MVC

Posted
  • MVC
Posted

Is this a first year ICT course?

I would tell you that Power On Self Test is the first thing the computer does but 13 other users have already told you that.

What I'm intrigued about is how your ICT instructor with supposedly a "degree" does not know this.

I think a rather simple way of demonstrating her error in a productive manner would be just to power on a computer, and show her how she's incorrect, rather than making an argument out of this.

Grand Master

Hell-In-A-Handbasket

Posted
Posted

its a degree in automotive, or cosmotoligy

id argue with her just for the simple fact of the "i'm better then you" complex she has

What I'm intrigued about is how your ICT instructor with supposedly a "degree" does not know this.
Grand Master

Joel

Posted
Posted

Your teacher is a moron. Tell her to take a formatted harddrive with no OS on it and install it in a computer. Then tell her to turn the computer on. Ask her where the text is coming from if there's no OS installed on the drive yet. That'll shut her up.

Even better, tell her to remove the harddrive and turn the computer on.

Enthusiast

Nickyyy

Posted
  • Author
Posted

That would not of worked.

Could a mod please close this now? I think I have all the input thanks guys and girls :)

And btw just to make absoloute clear my teacher is a great teacher but sometimes we argue! This time I just felt I was right :) lol

Grand Master

Angel Blue01

Posted
Posted

There's your source.

Don't feel bad, I had a teacher tell me earlier this semester that POP was used in both sending and receiving E-mail when she explained that its used only in receiving E-mail to a confused classmate of mine a year ago! And she has her Phd...

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