This question already has an answer here:

I have a SSD with 2 partitions. The first one belongs to Win10 and it worked fine. I installed Ubuntu 15.10 on the second one and it also works fine.

Problem is : When I boot, Grub is correctly displayed and shows both OS. If I select Ubuntu, I can boot without issue and can even access to the Windows' partition. But if I want to boot on Win10, it displays a black screen (like it'll start normally) for a few seconds (perhaps 2 ou 3) then go back to Grub without any message.

I'm pretty new to Ubuntu but kinda excited about it, but as a graphic designer, I still need my Windows (Adobe) from time to time. If anyone has a clue, I'd be glad to hear it.

Thank you guys.

marked as duplicate by David Foerster, Eric Carvalho, Charles Green, Yaron, vidarlo Feb 4 '18 at 13:44

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • If you start the windows boot loader whitout grub does windows start. (press F12, F9, F10, etc. while your PC boots; boot device order and select windows boot loader) – Info-Screen Jan 25 '16 at 8:49
  • I tried but I only have 2 options : SSD and normal drive. Didn't work. – Jovana Jan 25 '16 at 19:06

Edit /boot/grub/grub.cfg

Find the Windows menu entry (looks like)

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows 10 (loader) (on /dev/sdXX)'


chainloader +1


ntldr /bootmgr 

It did the trick.

  • I used this method, but I had to do it through Grub Customizer. – Alexiy Apr 11 '16 at 11:39
  • 3
    My bloody word!! This worked lol 3 hours later and 1 line fixes me – Jamie Hutber Oct 10 '16 at 15:13
  • Excuse me, I was setting up for a few times 'ntldr /bootmgr', What should I do to leave it forever? (I did it by 'sudo' but sometimes it resets!) – M. Mariscal Dec 4 '16 at 22:09
  • 4
    Coming in a bit late, but in order to fully persist these, you can't edit grub.cfg, as suggested initially. You need to edit /etc/grub.d/40_custom and add the whole Windows entry there, creating a new one (as suggested here: ubuntuforums.org/…). This one will stay there even if you upgrade your Linux or run 'upgrade-grub' – ravemir Aug 12 '17 at 17:22
  • 1
    Did not work for me on Ubuntu 19.04. I have to use my EFI loader menu ("BIOS" sort of thing) to load my Windows :) – kolypto Aug 1 at 8:30

First of all you upgrade your grub.

    sudo update-grub2

If the above command didn't work, Then you download a windows iso file and also install 'winusb' application which is used to make bootable images of windows, if you have a cd it's fine.

Remember the partition name of your ubuntu. Now you from from windows usb or cd. Now you click on repair this pc and troubleshooting startup options.

It will automatically replace your grub and now you will be able to boot into windows but not into ubuntu.

Now you either install a brand new ubuntu or try working around with reparing it.

If you are going to install brand new ubuntu then i would suggest you to install the boot-loader(Grub2) on the root file system itself.

Then you install EasyBcd application for windows and then link the boot loader to the ubuntu partition, as this the safest way to go on, so that if you have any updates of grub or windows boot-loader there wouldn't be any trouble for you in future.

Click here To watch a video about installing in the safest way.

I have installed 5 Linux Systems and 1 Windows os using the method mentioned above, I haven't got any problem till now.

  • Oh. Thank you. If possible, I would avoid to reinstall ubuntu again, as I already have a bunch of files and config on it, but I will definitely try to follow your advice. Thanks again. – Jovana Jan 25 '16 at 10:18

this worked for me:

  1. install win 8/10
  2. boot on a live linux cd (i used boot-repair-disk-64bit.iso), any from where you can run gparted.
  3. shrink the win partition to make room for your linux.
  4. AND NOW THE REALLY IMPORTANT: restart windows, and then open file explorer (the yellow one) and see that your drive C: still thinks it owns the whole disk.
  5. right click on drive C: and chose properties/tools and click check.
  6. now windows will check and verify the new size of the win partition.
  7. you may have to reboot in to win a couple of times, but finally win knows the size and position of its partition(s)
  8. now you can install ubuntu or whatever - and should it not work, boot-repair-disk-64bit.iso will make it work fast.
  • 1
    it is best to resize windows partitions from Windows. – ravery Oct 8 '17 at 5:08

Not the answer you're looking for? Browse other questions tagged or ask your own question.