Can a PC run without a BIOS?

Question

On bootup, a BIOS is required for all of the basic tasks, and it then hands over control to the Operating System, to do everything else.

But, if a UEFI is just a BIOS but faster, could you technically run a computer without a BIOS?
Im not sure if a BIOS has a job other than boot up, that a UEFI can't do, if there is such a task, then my answer is no, and if there isn't such a task, then my answer should in theory be Yes.

Anonymous · Answer

No it cant............

? · Answer

UEFI is a BIOS, so the correct name should be "UEFI BIOS" and the old version "Legacy BIOS".  But most people just say UEFI and BIOS.

You still need some "legacy" BIOS compatiblity to boot older OS's and to boot non-signed systems.

? · Answer

BIOS is the Basic Input/Output System, that tells your computer what to do when you hit power. without such instructions, nothing would even show up on the screen, let alone look for windows.
UEFI does the same thing, just with a more advanced interface, and usually a mouse cursor. honestly, if UEFI were just a hair more advanced, you wouldn't need Windows!
but every computer uses different parts, so they need different "instructions" on how to start up when power is pushed.

Robert J · Answer

A PC (or any computer that can start without manual programming) needs the initial boot code in ROM (typically EPROM / EEPROM / FLASH ROM etc).

Whether you call it BIOS, UEFI or whatever, there must be a startup program built in that runs when the CPU starts from a hard reset.

In a PC, that checks the hardware configuration and initialises various devices for basic functions, then loads the next stage boot program from whatever device is set as the boot one.

After that is loaded, it transfers control to that program for it to continue loading the operating system.

In a lot of other types of computer systems, such as appliances or vehicle engine control units, the whole program is in the same ROM device so it just runs directly from that as soon as it is switched on.

Old Man Dirt · Answer

A bios chip does have its own language. To use these commands the instructions have to be written in "machine language". Programing at this level is very tedious. It does run faster, but a lot of things you like about your computer are only possible because some one else did the work to create a command structure that you presently use.
As I understand it the latest generations of computers are using UEFI because the limitations of BIO have been exceeded. Functionally it is a BIOS, but because of technical differences it is called UEFI.

Can a PC run without a BIOS?

5 Answers