How to Enter BIOS / UEFI and Difference between the two

BIOS and UEFI are two computer firmware interfaces that act as an interpreter between the operating system (eg Windows) and the computer firmware. Both of these interfaces are used at PC startup to initialize hardware components and start the operating system stored on the hard drive.

BIOS (Basic Input Output System) works by reading the first sector of the hard drive which has the address of the next device to initialize or the code to execute. The BIOS also selects the boot device that must be initialized to boot the operating system. Since the BIOS has been used since the beginning (it has existed since the MS-DOS era), it still works in 16-bit mode, limiting the amount of code that can be read and executed from the firmware ROM.

UEFI (Unified Extensible Firmware Interface) performs the same task but in a slightly different way. Stores all initialization and startup information in an .efi file instead of the firmware. This file is stored on the hard drive inside a special partition called EFI System Partition (ESP) . The ESP partition also contains the boot loader programs for the operating system installed on the computer.

UEFI is intended to completely replace the BIOS and introduce many new features and enhancements that cannot be implemented via BIOS. Some of these features will be discussed below.

Removing Size Limits [BIOS Vs UEFI]

The BIOS uses the Master Boot Record (MBR) to save the information on the disk data while UEFI uses the GUID partition table ( GPT ). The main difference between MBR and GPT is that MBR uses 32-bit entries in its table, which limits the total physical partitions to max 4. Each partition can have a maximum size of 2TB , instead GPT uses 64-bit entries in its table going to greatly extend support for hard disk size possibilities. This (big) advantage leads users to convert MRB disks to GPT in order to remove any maximum size limit.

Besides that, UEFI supports larger HDDs and SDDs. UEFI’s theoretical size limit for bootable drives is greater than nine zettabytes, while the BIOS can only boot from drives of 2.2 terabytes or smaller.

Speed ​​and performance [BIOS Vs UEFI]

As UEFI is platform independent, it may be able to improve boot time and PC speed . This is especially true when large hard drives are installed in the computer. This improvement depends on how UEFI is configured to run. UEFI can work better when initializing hardware devices. Normally this speed boost is a fraction of the total boot time, so you won’t see a huge difference in the overall boot. However, developers can also use the UEFI shell environment to execute commands from other UEFI apps further optimizing system performance.

Security [BIOS Vs UEFI]

The ” Secure Boot “, that is, the ‘ secure boot is a UEFI functionality that is implemented in Windows 8 and is now the standard for Windows 10. The biggest benefit of UEFI is its security than the BIOS. UEFI can only allow genuine drivers and services to be loaded at boot, ensuring that no malware can be loaded when the computer starts.

Microsoft has implemented this feature to combat piracy issues in Windows, while Mac has been using UEFI for some time now. Secure Boot works by requiring a digital signature of the boot loaders which should require the digital signature of the kernel. This process continues until the operating system is fully booted. This secure boot feature is also one of the reasons it is harder to install another operating system on a Windows machine.

Why choose UEFI?

One of the reasons for choosing UEFI over BIOS is that Intel has started to abandon the “traditional” BIOS since 2020.

UEFI provides the following features and benefits:

  1. Language: the BIOS is written in assembler, while UEFI is written in a simpler C language.
  2. Drive: UEFI supports larger HDDs and SDDs. UEFI’s theoretical size limit for bootable drives is greater than nine zettabytes, while the BIOS can only boot from drives of 2.2 terabytes or smaller.
  3. Drivers: UEFI has complex but discrete drivers, while the BIOS uses the drivers in option ROM (read-only memory). With the BIOS, updating the hardware requires a new adjustment of the ROMs for compatibility. This specification applies to separately written and updatable UEFI drivers.
  4. Boot time: In most cases, UEFI provides a faster boot time for the operating system.
  5. Security: UEFI offers enhanced security features. “Secure Boot” prevents unsigned or unauthorized applications from starting your computer. The operating system must contain a recognizable key. Without Secure Boot enabled, a PC is vulnerable to malware that damages the boot process.
  6. Data Processors: UEFI works in 32- or 64-bit mode. The BIOS only runs in 16-bit mode and can only use 1 MD of executable memory.
    GUI: UEFI provides a more intuitive graphical user interface that you can navigate with a mouse and keyboard, unlike the BIOS.

Why choose BIOS?

Some reasons why a user might choose Legacy BIOS instead of UEFI are:

  1. The BIOS is ideal if you don’t need precise control over the operation of your computer.
  2. The BIOS is sufficient even if you only have small drives or partitions. Although many newer hard drives exceed the 2TB limit of the BIOS, not all users require that amount of space.
  3. UEFI’s “Secure Boot” feature can cause OEMs to prevent users from installing other operating systems on their hardware. If you use BIOS, avoid this problem.
  4. The BIOS provides access to hardware information in the interface, while not all UEFI implementations do. However, the hardware specifications are accessible within the operating system.

Some newer PCs also allow you to run UEFI in legacy BIOS mode . Users who want to keep machines running older operating systems, including Windows 7, will need to enable this feature.

How to Enter BIOS / UEFI

Depending on the motherboard manufacturer, you need to press specific keys or a combination of keys on the keyboard to enter UEFI mode . Although the splash screen shows the keys you need to press, it can be confusing for beginners. If you find yourself in this situation, you can boot into UEFI mode directly from Windows. This eliminates the need to press the relevant keys as fast as possible at boot time.

The ‘ Boot UEFI in Windows is not difficult. However, you can only do this if your motherboard supports or has a UEFI chip on it. If your motherboard doesn’t support UEFI, you can’t boot UEFI from Windows. That said, most modern motherboards are equipped with a UEFI chip and support both UEFI and legacy BIOS .

If you don’t know or are not sure if your motherboard supports UEFI or not, you can easily check this directly from Windows.

There are several ways to check if you are using UEFI or BIOS. Windows displays all system information in a single app called System Information . By accessing the System Information application you can find out if you are using BIOS or UEFI. Here’s how to do it

  1. Press Win + R, type msinfo32and press Enter . This action will open the System Information app.
  2. In the window that opens, look for the entry ” BIOS mode“. If you see UEFI, your system is using UEFI bios. If you see “ Legacy“, your system is using Legacy BIOS.

If you have a problem accessing the BIOS , you should always check this setting because you will be able to understand exactly what the system is using.

Enter UEFI from Windows Settings

To boot into UEFI from the Settings panel , you need to use the advanced boot options.

  1. Search for ” Settings” in the Start menu and open it. Go to ” Update & Security -> Recovery” and click the ” Restart Now ” button in the Advanced Startup section.
  2. In the advanced boot screen go to ” Troubleshoot -> Advanced Options” and click on the option ” UEFI Firmware Settings“.
  3. On the next screen click the Restartbutton and you will be taken to the UEFIscreen .

Enter UEFI via Command Prompt

You can also boot UEFI from Windows by running a single command.

  1. Search for Command Promptin the Startmenu , right-click and select the “ Run as administrator ” option .
    2. At the command prompt, run the following command:

shutdown / r / fw

  1. Windows will show a warning message saying that the system will be restarted in less than a minute. Close the warning message and save all your work. The system will automatically reboot and boot into UEFI mode.

How to enter the BIOS (classic)

It is possible to enter the classic BIOS when restarting the computer in a very simple way. What you need to do is restart your computer and quickly press one of the function keys to enter the BIOS (eg F2  or  F10 key ). The key to press at startup depends on the make and model of the computer. Here is a list with the main computer models and the relative button to press at startup to enter the Bios:

ASUS : F2 for all
Acer PCs : F2 or DEL
Dell : F2 or F12
HP : F10
Lenovo (laptops): F2 or Fn + F2
Lenovo (desktops and ThinkPads): F1.
Microsoft Surface key : Press and hold the volume up button.
Samsung : F2
Toshiba : F2
Zotac : DEL

Once the BIOS opens you will be able to navigate the menu using the arrows on the keyboard and you will see such a screen


by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

Leave a Comment