
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
- How to check if your PC uses BIOS or UEFI using setupact.log
How to check if your PC uses BIOS or UEFI using System Information
To confirm whether your computer is using UEFI or BIOS with System Information, use these steps:
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Open Start on Windows 10.
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Search for System Information and click the result.
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Quick tip: Alternatively, you can also use the Windows key + R keyboard shortcut to open the Run command, and then type msinfo32, and click the OK button to open System Information.
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Under the “System Summary” section, find the BIOS Mode. If it says BIOS or Legacy, then your device is using BIOS. If it reads UEFI, then you’re running UEFI.
System Information BIOS mode BIOS System Information BIOS mode UEFI
How to check if your PC uses BIOS or UEFI using setupact.log
To find out if your device is using BIOS or UEFI checking the setupact.log file .
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Open File Explorer.
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Type the following path in the address bar and press Enter.
%SystemRoot%\Panther
Windows Panther folder -
Open the setupact.log file using the Notepad.
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Use the Ctrl + F keyboard shortcut to open Find.
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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.
- If the line reads
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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.