Windows 8 and 8.1 Forums


Installing Windows 8.1 as non-UEFI

  1. #1


    Posts : 241
    Windows 8.1x64 Pro

    Installing Windows 8.1 as non-UEFI


    Hi, is it possible to install Windows 8.1 as Legacy with MBR? Or only as UEFI with GPT? I'm kind of confused with all this UEFI business, I always used MBR in my Windows installations. Also, Truecrypt does not support UEFI, so if installing Win8.1 I should do it as legacy.
    Also, how can I control during the install process if I want to set my system installation as UEFI or Legacy?
    Thanks

      My System SpecsSystem Spec

  2. #2


    Portsmouth Hants
    Posts : 772
    Windows 8.1 Pro with Media Center


    Yes, it installs fine with MBR on non GPT motherboards, and with UEFI - you need a motherboard that is UEFI 2.0 compliant - you may need to check your manufacturers documentation how to access the boot options.
    UEFI (Unified Extensible Firmware Interface) - Install Windows 8 with
      My System SpecsSystem Spec

  3. #3


    Posts : 241
    Windows 8.1x64 Pro


    Quote Originally Posted by fafhrd View Post
    Yes, it installs fine with MBR on non GPT motherboards, and with UEFI - you need a motherboard that is UEFI 2.0 compliant - you may need to check your manufacturers documentation how to access the boot options.
    UEFI (Unified Extensible Firmware Interface) - Install Windows 8 with[2]=Installation%20and%20Setup
    So basically if during install I see those 5 partitions being created it means that it will be a UEFI install? Yes, my mobo is UEFI 2.0 compliant.
    AFAIK the only performance benefit of UEFI is a slightly faster boot time as compared to legacy.
      My System SpecsSystem Spec

  4. #4


    Posts : 5,592
    ME, XP,Vista,Win7,Win8,Win8.1


    Your specs: Sony VAIO Windows 8x64 Laptop.

    VAIO User Guide | Why does a message appear and Windows fail to start when I turn on my VAIO computer?


    How do I downgrade my OEM Windows 8 to Windows 7 P... - Sony's Community Site

    Quote Originally Posted by PeterT
    Currently we do not have any support for Windows 8 downgrade to Windows 7 at this moment. We are investigating this area and drivers to see if this is possible. We should have some kind of an update by Jan or Feb 2013 in terms of what model is eligible or not.


    Sony Community Manager
    Sr. Software Engineer
    Peter Tat





    Sony eSupport - Windows® 7 Clean Install Instructions for Windows® 8 PCs

    Quote Originally Posted by Sony
    1.With the computer powered off, press the Assist button to enter the VAOCare Rescue Mode Boot screen.
    2.Select the ‘Start BIOS setup [F2]’ option to proceed to the system BIOS.
    3.Once inside the InsydeH2O Setup Utility, use the arrow keys to select the ‘Boot’ list.
    4.With the ‘Boot Mode’ option selected, press enter to change the setting from UEFI to Legacy. or (UEFI/Legacy if a option)
    5.Use the arrow keys to proceed to the ‘Exit’ menu.
    6.Select the ‘Save Changes’ option and press Enter.
    7.After saving the changes, select Shutdown.



    A good read.
    Sony eSupport - Windows® 7 Clean Install Instructions for Windows® 8 PCs

    How do I downgrade my OEM Windows 8 to Windows 7 P... - Page 2 - Sony's Community Site

    Installing Windows 8 in Legacy, would be the same above.
      My System SpecsSystem Spec

  5. #5


    Posts : 241
    Windows 8.1x64 Pro


    Thanks theog for those links. I already have Win 8 in my Sony Vaio. I'm mostly concerned with my PC for which I have updated my system specs in the profile. I have Win7x64 in my PC and want to upgrade to Win8.1, but prefer a clean install rather than upgrading.
      My System SpecsSystem Spec

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