How do I reinstall Windows 10 while keeping my dual boot configuration? I want to do a clean install of Windows 10. I have Ubuntu 16.04. I upgraded from Windows 7 to Windows 10.


  • The latter is specific for Win 10.
    – user308164
    Aug 23, 2016 at 14:01
  • @luchonacho That one is also specific to Ubuntu 14.04. This question is specific to Ubuntu 16.04.
    – EKons
    Aug 23, 2016 at 14:36
  • @karel That one is specific to Windows 7.
    – EKons
    Aug 23, 2016 at 14:38
  • Welcome to the community, Isaiah!
    – EKons
    Aug 23, 2016 at 14:38
  • Very important to know if UEFI or BIOS. IF Windows 10 was pre-installed by vendor it will be UEFI. But if you upgraded a Windows 7 to Windows 10 then it probably is BIOS. A few Windows 7 systems were UEFI. Either ways best to use Windows to shrink the main (c: drive) partition to make room and reboot immediately to let it run chkdsk. Also make sure Windows fast start up is off as that is hibernation and will not work to dual boot.
    – oldfred
    Aug 23, 2016 at 14:54

1 Answer 1


The problem in this situation is that, if you install Windows 10, it will overwrite the MBR. Windows thinks it's the only OS in the world.

  • Install Windows using Windows installation media.
  • Boot using an Ubuntu Live CD. Choose the "Try Ubuntu" option.
  • Open a terminal and type sudo grub-install /dev/sdX where sdX is your hard drive. The first hard drive is called sda, so if you only have one hard drive, replace sdX with sda.
  • Press . After the command is executed run sudo update-grub
  • After the command is executed, reboot your system and remove the live CD or USB when asked to in order to prevent booting into it.
  • Voila! You will have grub restored with both OSes.
  • I suggested an edit. If you don't agree with some of the changes, improve the answer. If you don't agree at all, reject.
    – EKons
    Aug 23, 2016 at 16:43
  • It is not showing a suggested edit
    – Ceda EI
    Aug 23, 2016 at 17:16
  • What? I'm sure I suggested it, the post even has the "Thanks for your edit!" indication for me. Check again; tell the truth.
    – EKons
    Aug 23, 2016 at 17:17
  • I have never got an suggested edit to my answer. Does it show that in notifications. If so, it is not there, nor in feed, neither in my profile
    – Ceda EI
    Aug 23, 2016 at 17:21
  • Then you might have low rep count yet... I don't now exactly how many rep you need to review your own posts. Anyways, peers are there to review it for you. And yes, it shows up in the notifications.
    – EKons
    Aug 23, 2016 at 17:27

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