The grub.cfg entry that you see should be this one:
### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows Boot Manager (on /dev/sda2)' --class windows --class os $menuentry_id_option 'osprober-efi-8A05-F956' {
savedefault
insmod part_gpt
insmod fat
set root='hd0,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 8A05-F956
else
search --no-floppy --fs-uuid --set=root 8A05-F956
fi
chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
set timeout=10
fi
### END /etc/grub.d/30_os-prober ###
besides stupidly and needlessly complex,it seems like fine.
Are you sure that you see twice the 'Windows Boot Manager (on /dev/sda2)' ?
What happens when you are booting if you press F12? (or F9, it depends from the specific system)
You should be able to choose between the Windows Bootmgr (bypassing the GRUB2) and GRUB2.
It *sounds* like there is a "conflict" of some kind with actual names of the files, it has to be understood which is which and what is inserted (and also which is default) in the NVRAM.
There is a tool called boot-repair for Linux that seemingly can make things even worse , you didn't happen to have used it, by any chance?
http://ubuntuforums....d.php?t=2234019
Are you sure that the file /efi/Microsoft/Boot/bootmgfw.efi is the actual Windows BOOTMGR and which other files do you have (i.e. /efi/boot/bootx64.efi and /efi/ubuntu/grubx64.efi ) ?
Wonko