Ubuntu – Windows doesn’t start anymore from the grub boot menu

bootdual-bootgrub2windows 10

I have an SSD with 2 partitions.
The first partition belongs to Windows 10 and it worked fine.
I installed Ubuntu 15.10 on the second partition and it also works fine.

When I boot, grub is correctly displayed and shows both Windows and Ubuntu. If I select Ubuntu it can boot without issue and I can even access the Windows partition from Ubuntu, but if I try to boot Windows 10 it displays a black screen (like it will start normally) for a few seconds (perhaps 2 or 3 seconds) and then it goes back to grub without showing any message.

Best Answer

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)'

After

chainloader +1

Write

ntldr /bootmgr 

It did the trick.

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