Frequently Asked Questions

1. On Windows, “System Information” in Start panel and under BIOS Mode, you can find the boot mode. If it says Legacy, your system has BIOS. If it says UEFI, well it’s UEFI.
2. Alternative: You can launch a command prompt window as administrator and look for the path of the bootloader by running bcdedit in the cli/command prompt 
   # bcdedit 

Here, in the Windows Boot Loader section, look for Path. if the file extension for /Windows/System32/winload is .exe, your system uses legacy BIOS. If the extension is .efi, your system uses UEFI.

Image here

Another way to check UEFI or BIOS in Windows

If you are using Windows 10, you can check whether you are using UEFI or BIOS by opening File Explorer and navigating to "C:\Windows\Panther". Open the file setupact.log and search for the below string.
 Detected boot environment

Check if you are using UEFI or BIOS on Linux

The easiest way to find out if you are running UEFI or BIOS is to look for a folder /sys/firmware/efi. The folder will be missing if your system is using BIOS.
<image here>

/sys/firmware/efi exists means system uses UEFI

• Alternative: The other method is to install a package called efibootmgr.
  On Debian and Ubuntu based distributions, you can install the efibootmgr package using the command below:

sudo apt install efibootmgr

Once done, type the below command:
sudo efibootmgr

If your system supports UEFI, it will output different variables. If not you will see a message saying EFI variables are not supported.