59877: Acronis True Image: how to distinguish between UEFI and Legacy BIOS boot modes of Acronis Bootable Media

Last update: 20-08-2020


This article explains how to find out whether Acronis Bootable Media boots in UEFI or Legacy BIOS mode. Keep in mind that bootable media should boot in the same mode as your system to correctly perform restore or clone operation.

The mode your system boots in is shown during the initial machine boot:

In Windows 8 and 10, you can also check the boot mode using System Information:

1) Press Win+R, type msinfo32 and press Enter to open System Information

2) Look for the BIOS Mode entry. If your computer uses BIOS, it will display Legacy. If it is using UEFI, it will display UEFI.



WinRE/WinPE-based media (default)

Linux-based Bootable Media

1. WinRE/WinPE-based media (default)

If you chose the second option in the Rescue Media Builder wizard, "WinPE-based media with Acronis Plug-In", discovering whether it is started in UEFI mode or Legacy BIOS/CSM is different.

Booting WinPE-based media looks identical in both UEFI and Legacy BIOS modes. The difference could be told only by looking up in the registry after Acronis True Image main window appears (steps 6 and 7 in the table below). Click here to skip to the instructions part.

Booting stage UEFI boot mode Legacy BIOS/CSM boot mode
1. WinPE loader starts up "Press any key to boot from CD or DVD..." text is displayed
2. WinPE environment starts up Windows Logo
3. WinPE startup scripts are executed "wpeinit" is displayed
4. Acronis True Image WinPE application starts up "X:\Program Files\Acronis\TrueImageHome\trueimage_starter.exe" is shown on the screen
5. Acronis True Image is ready for use Acronis True Image window
6. Close Acronis True Image window by clicking on the red cross in the right corner of the window. Do not confuse it with the black command prompt - the black window should be kept open
7. Click on the black command prompt window, type regedit then press Enter on the keyboard to launch a registry editor "regedit" command
8. Browse to the section HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control and look at the value of the "PEFirmwareType" parameter "2" means UEFI boot mode
"1" means Legacy BIOS/CSM boot mode

9. To access Acronis True Image again, press Up and Down arrows on keyboard to bring the command back in the command prompt, then press Enter on keyboard to open Acronis True Image window


2. Linux-based Bootable Media

The table below illustrates the booting process of the Linux-based Bootable Media. You have this type of media if you have chosen the first option, "Acronis Bootable Media", in the Rescue Media Builder.

By simply looking at how the media starts up, you can tell whether it is booting in UEFI mode or Legacy BIOS/CSM.

Booting stage UEFI boot mode Legacy BIOS/CSM boot mode
1. Acronis Loader initializes "Starting ... UEFI Loader" is displayed
"Starting Acronis Loader" is displayed
2. Acronis Loader boot menu Black-and-white boot menu
Colorful boot menu
3. Acronis Linux environment starts up "Please wait ..." text appears
Logo and patents
4. Acronis True Image Linux application starts up "Loading, please wait..." is displayed
5. Acronis True Image is ready for use Acronis True Image window