1.    17 Jul 2015 #1
    Join Date : Jul 2015
    Posts : 16
    Windows 10

    Dual Booting with Windows 8.1


    I have the ESD for Windows 10 built 10240 . I need to clean install it on a different drive and dual boot it with Windows 8.1. Can I simply boot with the 10 ISO (in UEFI boot) and clean install it on a different drive?

    Would I then be able to dual boot it with my activated 8.1 copy?
      My System SpecsSystem Spec

  2.    17 Jul 2015 #2
    Join Date : Jul 2014
    San Jose, California
    Posts : 1,870
    Ubuntu14.04x64 MintMate17x64 Win10Prox64

    The procedure below will allow you to boot Windows separately or in dual boot configuration.
    Here's what I recommend to do:
    1. Disconnect the drive containing Windows 8.1
    2. Install Windows 10 with one drive connected.
    3. After step 2, reconnect the drive containing Windows 8.1
    4. Boot up Windows 8.1. Open disk management and take a note of the drive letter of Windows 10 OS.
      NOTE: if you boot up Windows 10, then take a note of Windows 8.1 drive letter
    5. Open Admin command prompt and type: bcdboot X:\windows where X: is the drive letter of Windows 10 (Windows 8.1 if you boot from Windows 10 in step 4)
    6. Reboot the PC. You should have a dual boot screen.

    NOTE: To break off the dual boot setting, Win+R->msconfig->boot and delete the none default entry on the list.
    Last edited by topgundcp; 17 Jul 2015 at 04:57.
      My System SpecsSystem Spec

  3.    17 Jul 2015 #3
    Join Date : Dec 2013
    Portsmouth Hampshire
    Posts : 1,130
    Windows 10 x86 14383 Insider Pro and Core 10240

    If you have a notebook, or single hard drive etc., where disconnecting the drive is out of the question, you may wish to use this method.
    Assuming you have a clean partition or free allocated space or there is enough space to extend for another partition to be created on your disk.

    Windows 10 - Dual Boot with Windows 7 or Windows 8 - Windows 10 Forums

    scroll down to:
    5. To Install Windows 10 as Dual Boot with ISO inside Windows 7 or 8

    If you still have the c:\$Windows~BT\Sources\install.esd

    you do not need to create an iso file - you can just run setup from c:\$Windows~BT\Sources\setup.exe
      My System SpecsSystem Spec


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