How to know if my computer is using EFI/UEFI or BIOS firmware interface?

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I am not able to migrate my Windows PC into a virtual machine using Parallels® Transporter™. Migration fails on detecting the operating system type.


Your PC most likely has a GPT partition on the hard drive and is using EFI/UEFI instead of BIOS.


Parallels Desktop supports migrating computers with GPT partitions and EFI/UEFI starting from version 10. Parallels Desktop 9 and earlier do not support migrating computers with GPT partitions and EFI/UEFI.

To determine whether your PC is using BIOS or EFI/UEFI please follow the steps below:

  1. Start your PC.
  2. Go to Start > Computer.

  3. Navigate to C:\Windows\Panther\setupact.log.

  4. Open setupact.log.
  5. Search for this string:

    Callback_BootEnvironmentDetect: Detected boot environment:

    It should tell you whther the boot environment is BIOS or UEFI:

    Code:Callback_BootEnvironmentDetect: Detected boot environment: BIOS
    Code:Callback_BootEnvironmentDetect: Detected boot environment: UEFI

In Windows 8 and Windows 8.1, if the setupact.log file is missing in the Panther folder, you can check the Boot Environment using the following steps:

  1. Press Win + R > type msinfo32 and press Enter.

  2. Look for the BIOS Mode entry.

  3. If the value listed is Legacy, then the Boot Environment is BIOS, otherwise the respective Boot Environment will be listed


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unknown locale 'ca'