BIOS or UEFI?

How to check if your PC is using BIOS or UEFI on Windows 10

Wondering whether your Windows 10 device is using BIOS or UEFI? Here's how to tell.

BIOS (Basic Input Output System) is a small piece of software stored on a non-volatile chip on the motherboard that instructs the system the steps to boot up and configures system hardware, such as hard drive, keyboard, mouse, processor, memory, and others.

Although BIOS has been around for many years and helps the operating system to interact with the hardware, it’s a system with some limitations, such as drive partition support, slow startup times, and it doesn’t offer boot security.

UEFI (Unified Extensible Firmware Interface) is a newer system that replaces BIOS that comes with its own boot manager, delivers faster startup times, improves networking support, support large partitions on drives, and it offers security features to protect your system against bootkit and other malware attacks during startup.

While most devices today come with UEFI support, there are still many computers (especially older ones) that are still using BIOS. If you want to know which type of system your PC, laptop, or tablet is using, you can check this information in at least two different ways on Windows 10.

In this guide, you’ll learn two ways to check whether your device is using BIOS or UEFI.

How to check if your PC uses BIOS or UEFI using System Information

The easiest way to tell whether your computer is using UEFI or BIOS is to check Windows 10’s System Information.

  1. Open Start.

  2. Search for System Information and click the result.

  3. Quick Tip: Alternatively, you can also use the Windows key + R keyboard shortcut to open the Run command, and then type msinfo32, and click OK to open System Information.
  4. Under “System Summary,” look for BIOS Mode. If it says BIOS or Legacy, then your device is using BIOS. If it reads UEFI, then you’re running UEFI.

  5. System Information BIOS mode BIOS
    System Information BIOS mode BIOS
    System Information BIOS mode UEFI
    System Information BIOS mode UEFI

How to check if your PC uses BIOS or UEFI using setupact.log

Alternatively, you can also check the setupact.log file to find out if your device is using BIOS or UEFI.

  1. Use the Windows key + R keyboard shortcut to open the Run command.

  2. Type the following path and click OK.

%SystemRoot%\Panther
  1. Windows Panther folder
    Windows Panther folder
  2. Open the setupact.log file using the Notepad.

  3. Use the Ctrl + F keyboard shortcut to open Find.

  4. On Find, search for Detected Boot Environment.

    • If the line reads Callback_BootEnvironmentDetect: Detected boot environment: BIOS, then your computer is using BIOS.
    • If the line reads Callback_BootEnvironmentDetect: Detected boot environment: UEFI, then your device is using UEFI.
  5. SetupAct.log file on Windows 10
    SetupAct.log file on Windows 10

If you also need to find out the version of the BIOS or UEFI you’re using, you can refer to this guide.