I think the problem is everything between the lines
### BEGIN AUTOMAGIC KERNELS LIST
and
### END DEBIAN AUTOMAGIC KERNELS LIST
gets auto regenerated when a new kernel is installed, and update-grub is run.
see bug 21412 and bug 2646.
What happens if you copy the windows entry above ### BEGIN AUTOMAGIC KERNELS LIST and run sudo update-grub ?
I think the problem is everything between the lines
### BEGIN AUTOMAGIC KERNELS LIST
and
### END DEBIAN AUTOMAGIC KERNELS LIST
gets auto regenerated when a new kernel is installed, and update-grub is run.
see bug 21412 and bug 2646.
What happens if you copy the windows entry above ### BEGIN AUTOMAGIC KERNELS LIST and run sudo update-grub ?