[CentOS] Dual boot C7 with Window 10

Tue Apr 19 11:56:42 UTC 2016
Richard <lists-centos at listmail.innovate.net>

> Date: Tuesday, April 19, 2016 07:42:44 -0400
> From: Jerry Geis <geisj at pagestation.com>
> I have a laptop with windows 10.
> I went into the Windows disk manager and shrunk the volume
> to make room for C7. That worked.
> I also changed the BIOS from secure boot to "both" (secure/legacy)
> I installed C7, went fine. About the time it was done I realized I
> never saw anything about "other" boot options (seems I saw that in
> the past).
> Anyway sure enough, got done and C7 boots fine - no option there for
> Windows.  I did searching and found I needed to add to the
> /etc/grub.d/40_custom the following:
> menuentry "Windows 10" {
>     set root='(hd0,1)'
>     chainloader +1
> }
> then re-run the grub2-mkconfig -o /boot/grub2/grub.cfg
> I then rebooted and sure enough I got the menu item for "Windows 10"
> however when I select it it does not boot.
> How do I get Windows 10 to boot again ?
> Thanks,
> Jerry

On my laptop, with windows-7, I have two differences.

  set root=(hd0,2)

not ... "(hd0,1)". I also don't have quotes, as you show, around that.

  insmod ntfs

between the "menuentry" and "set root" lines. 

Exactly where your windows partition lives may vary, so you may need
to play with that a little.