The BIOS (basic input/output system) of an IBM-compatible PC is a ROM which performs the POST (power-on self-test), initializes the peripheral devices, and provides a basic firmware interface.

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Can't enter BIOS password containing “!”

Yesterday, I added a password containing a ! to my BIOS. Unfortunately, the password prompt that asks for the password when you boot doesn't let you write a ! (i.e. the little * isn't added and it ...
72
votes
5answers
9k views

What are the functions of the BIOS while the operating system is running?

I always wondered whether the BIOS (apart from conducting POST, starting the bootloader and passing control to the OS after one presses the power button) has any purpose or function while the ...
62
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3answers
267k views

What is the difference in “Boot with BIOS” and “Boot with UEFI”

Now Windows 8 supports the UEFI bootloader and I have read that its different from the BIOS, but it's unclear to me after many searches on the Google. Some points in mind are below As we all know, ...
53
votes
9answers
18k views

Where is the BIOS stored?

From http://en.wikipedia.org/wiki/BIOS: BIOS software is stored on a non-volatile ROM chip on the motherboard. ... In modern computer systems, the BIOS contents are stored on a flash memory chip ...
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votes
5answers
7k views

Why is the first BIOS instruction located at 0xFFFFFFF0 (“top” of RAM)?

I know that BIOS loads its first instruction from 0xFFFFFFF0, but why this specific address? I've a bunch of questions and hope you can help me with some of them, at least. My questions: Why is the ...
42
votes
13answers
365k views

If USB is not listed in BIOS as a boot option, does that mean the machine can't boot from USB?

I just purchased an Asus Zenbook Prime UX31A-DH51 with Windows 8. I want to wipe the drive and do a clean install but USB is not listed as a boot option in the BIOS. Does this mean it is not possible? ...
41
votes
4answers
4k views

How computers display raw, low-level text and graphics

My ever-growing interest in computers is making me ask deeper questions, that we don't seem to have to ask anymore. Our computers, at boot, as far as I understand it, are in text mode, in which a ...
41
votes
2answers
21k views

Does Windows 8 support UTC as BIOS time?

Is there any way to use Windows 8 with time in UTC in BIOS? I know there is a way to do it in Windows 7 (in this question: Does Windows 7 support UTC as BIOS time?), but this solution makes my system ...
35
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11answers
5k views

What is the difference between BIOS and firmware?

Could anyone elaborate on the differences between BIOS and firmware please?
35
votes
9answers
12k views

Why must a computer have a BIOS?

The BIOS software is built into the PC, and is the first code run by a PC when powered on ('boot firmware'). When the PC starts up, the first job for the BIOS is the power-on self-test, which ...
35
votes
5answers
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Why should I choose (or not) AHCI over IDE in my PC's BIOS settings?

I've noticed in the BIOS settings of the newer PCs I own that I can configure the drive controller work either in AHCI (Advanced Host Controller Interface) mode, or else in IDE mode. I'm suspecting ...
33
votes
3answers
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What does “Legacy USB Mouse” support in a BIOS mean?

What does a "Legacy USB Mouse" option in a BIOS mean? Yes legacy usually means older revision, or obsolete. So legacy usb mouse means support for "old style usb mouses". That's not really ...
28
votes
3answers
4k views

What is a “Programmer” in the context of Bios Recovery?

I was reading about BIOS recovery and ran across the word "programmer". (No, it's not talking about people.) What is it referring to?
28
votes
3answers
2k views

Hard disk only recognized if it has already spun up

So here's a weird issue: When you first turn on this desktop computer, it does not recognize that it has a hard drive in it. However, if you then press the reset button, or turn it off and back on ...
28
votes
8answers
111k views

Is it possible to recover a computer from a failed BIOS update?

While attempting the update the BIOS on an Asus motherboard, i learned the Asus Update Utility for Windows doesn't fully support Windows 64-bit. It was able to erase the BIOS without problems, but ...
27
votes
2answers
3k views

When I hit DEL during start up, am I entering CMOS or BIOS?

For the longest time I assumed I was entering the BIOS setup and CMOS is a chip that holds the settings I set in BIOS in its memory. I recently read somewhere that when I am configuring the boot ...
26
votes
2answers
391k views

Asus UEFI/BIOS options - How to boot from DVD?

I just bought a new PC and the default installed OS is Windows 8. I want to install Windows 7 but when I go into the boot options screen I only have one option: Windows Boot Manager I can't find my ...
24
votes
3answers
5k views

Why do we need a boot loader?

After the BIOS, or something similar that serves as a firmware, is started, the control is passed to the bootloader, as far as I know. Why can't the BIOS load the OS kernel directly? Also, the ...
22
votes
2answers
980 views

Does the BIOS have some sort of generic 'drivers'

How does the BIOS control I/O devices without any form of drivers? For example how is an image displayed whilst the computer is booting if the BIOS doesn't have any drivers for the graphics card. ...
22
votes
8answers
25k views

Last BIOS time on Task Manager

Can someone tell me what that Last BIOS time is on the upper right corner of the task manager on Windows 8 Pro? Mine has always been 0.0. I guess it is not measuring the BIOS time properly so what can ...
21
votes
2answers
3k views

What is “flashing the BIOS”?

What does "Flashing the BIOS" mean? Are there benefits to flashing it? Is it safe? Should it be done inside or outside of an OS, for example my current Windows 7 installation?
21
votes
1answer
17k views

Using virtual box is it possible to set your virtual machine time to be different from host time

Using virtual box is it possible to set your virtual machine time to be different from host time. Say 1 year into the past. If I wanted to run the windows XP images provided by Microsoft from here. ...
21
votes
4answers
33k views

VT-x/AMD-V hardware acceleration not operational with VirtualBox

I am trying to install OS X with VirtualBox, on my Windows 7 laptop. I see the following error message: VT-x/AMD-V hardware acceleration has been enabled, but is not operational. Certain guests (e.g....
20
votes
2answers
6k views

How can the BIOS block virtualization?

I'm starting to work with Docker and after a few hours of trying to make it work, I found out that my BIOS was blocking it and that I needed to adjust the BIOS settings. I was told that the BIOS is ...
20
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2answers
3k views

Why are operating systems (usually?) unable to access BIOS settings?

Does the motherboard not provide a bus between the CPU and BIOS chip after bootup? If so, why not? If the CPU can control fan speed, I don't see why it shouldn't be able to control the BIOS config.
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8answers
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How can I take screenshots of the PC before it boots up?

How can I take a screenshot of the PC before it has started up? For example: If I wanted to take a screenshot of my BIOS and send it to the Network Admin for review Windows installation screenshots ...
18
votes
1answer
6k views

Windows 8/8.1 system clock changing randomly while powered on and in use

I cannot explain this any more clearly and it has literally driven me insane. A few weeks ago my netbook's Windows 8 system clock started changing randomly while it was powered on and being used, so ...
16
votes
6answers
1k views

How do you explain what the BIOS is to non-Super User?

In a particularly nerdy Facebook status update I mentioned that I had flashed my BIOS. One of my friends asked what the BIOS is. My question is: How do you explain what the BIOS is and does to a ...
16
votes
5answers
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Is there any way to boot Windows 7/8 using BIOS on GPT?

I'd like to know if there's a method to get Windows 7 or Windows 8 Developer Preview to install to a GPT disk on my traditional IBM PC BIOS setup. Windows 7, of course, rejects my GPT partition, ...
16
votes
1answer
3k views

What hardware device used to eat up 1.4GB of my 4GB RAM, and now suddenly after no hardware changes eats up 2.2GB?

This is more or less a continuation of What hardware device eats up 1.4GB of my 4GB RAM? While I have more or less accepted the solution there that for some mysterious reason, after a BIOS upgrade ...
16
votes
3answers
5k views

Change Linux Console's Default Monitor

Is there any way to specify which monitor the console is displayed on in Linux? Details: I have a 3 monitor setup with 2 video cards. When I boot the computer, the BIOS displays on the PCI graphics ...
15
votes
6answers
9k views

How to prevent Windows 7 from reading the BIOS time?

I'm using the "Time Limit" feature of Windows Live Family safety. I've placed a time restriction on my computer from 12 AM to 4 AM. However if someone changes the BIOS time, the Windows time will be ...
15
votes
5answers
785 views

Do POST beep codes also generate a numeric code for a POST test card?

My wife is an American Sign Language interpreter. She is currently interpreting for a student in a computing class. Today they were talking about BIOS and POST beep codes and the student asked the ...
15
votes
5answers
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How to know if my BIOS supports UEFI?

I recently bought a new Dell notebook for my girlfriend and I want to know if the computer comes with a UEFI BIOS, unfortunately I didnt find any information in the manual or on Windows, is there some ...
15
votes
6answers
28k views

Force Windows 8 to use UTC when dealing with BIOS clock

I have Arch Linux + Windows 8 on my laptop. In previous versions of Windows, there is a DWORD in the registry (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation\...
15
votes
1answer
262k views

How do I boot my Samsung laptop from a CD/DVD?

I have a Samsung Series 3 laptop and want to boot from an Ubuntu Live CD. When I press F10 to pull up the BIOS/boot configuration, I don't get an option to boot from the CD. Similarly, in the BIOS, ...
15
votes
5answers
102k views

Bypass BIOS password set by faulty Toshiba firmware on Satellite A55-S1065 laptop?

I want to rescue this 7 year old laptop that has been crippled by a glitch in its BIOS: 'A "Password =" prompt may be displayed when the computer is turned on, even though no power-on password has ...
15
votes
1answer
278 views

Why won't my motherboard work with two CPUs?

I (very) recently built a computer with the following specifications: (x2) Intel Xeon X5650; Supermicro X8DTI-F Motherboard; AMD Radeon R9 280X; 16GB DDR3 FB 1333MHz RAM (4x 4GB); 1TB Seagate ...
14
votes
8answers
10k views

Can a virus melt the CPU?

I was just wondering if a virus could melt a CPU by altering te voltage in the bios. :) (and no, I'm not planning on making that kind of a virus...)
14
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1answer
1k views

Incremental BIOS update or direct update to latest version?

I have been having some BSOD issues, and one of the recommendations to the STOP: Error that I have been experiencing is a BIOS update. I went to ASUS website and found the motherboard I am using ...
14
votes
4answers
20k views

PC shutting down after 30 minutes, even when on BIOS screen

I have a desktop PC that is just over a year old that I use daily for work. It's running Windows 8.1, has 16GB RAM and an i7 CPU. It has a 256GB Samsung 840 SSD (Windows + programs) along with a 1TB ...
13
votes
3answers
63k views

How to tell if windows 7 installer boot in EFI or BIOS?

I have a windows 7 64bit installation USB. I want to know if the windows 7 installer has booted into EFI or BIOS mode. I googled and found a solution here http://forums.bit-tech.net/showthread.php?t=...
13
votes
4answers
39k views

After Windows 8 installation I can't access BIOS settings anymore

Today I installed Windows 8 Consumer Preview on one of my notebook machines and I noticed that I can't access BIOS settings if I use the "Shut down" Windows option on Settings/Power menu. If I use the ...
12
votes
4answers
20k views

How can I change the BIOS serial number in VirtualBox?

VirtualBox sets the BIOS serial number of every VM instance to 0. It seems to be possible to change some BIOS settings, but I haven't seen anything that directly references the serial number. Can ...
11
votes
11answers
4k views

Switch on the computer automatically

Is there any way to switch on the computer automatically at a specific time. Is there any BIOS clock trigger mechanisms available to switch on automatically. EDIT: I have a Dell Inspiron laptop. Does ...
11
votes
2answers
69k views

How to create an EFI System Partition?

TL; DR How do I create an EFI system partition from scratch? How do I put the EFI firmware on it onces it is created? Long version I hava Toshiba T430 laptop. I received it with Windows 7 installed (...
11
votes
5answers
11k views

BIOS font, ROM font: Where to get them?

I was wondering if, and how I could get the fonts used in BIOS ROM (the font you see when entering BIOS setup and during early stages of boot). The same font is used in VirtualBox, when booting a VM. ...
11
votes
2answers
2k views

How many hours the PC has worked

I will buy a used PC and I want to know how many hours the PC has worked. I have already found : systeminfo | findstr /C:"Install Date" systeminfo | findstr /C:"BIOS Version" but I need to know ...
11
votes
3answers
86k views

How to get into BIOS when USB keyboard is not powered and have no PS/2 ports?

Just got a new Windows 7 PC (64-bit) with an Intel DH67CL motherboard. It's been working fine but I decided I wanted to try to get into the BIOS. Unfortunately I can't do it because my USB keyboard ...
11
votes
3answers
12k views

Linux on UEFI - how to reboot to the UEFI setup screen like Windows 8 can?

makeuseof.com explains that Windows 8 certified hardware has a new way to enter the UEFI setup screen (equivalent to BIOS). From How To Access The BIOS On A Windows 8 Computer: No longer do we ...