I'm running Linux Mint 17.2 and Windows 7. Today I was getting an error message when booting into Win: "BootMgr missing." I ran the common system repair tasks available on the Windows installation media. This seemed to have fixed it. But then Mint was gone from grub menu. So I booted from a live media of that and installed and ran boot-repair. It says everything went fine — and, from what I can tell from this log, it found Windows — but in the grub menu I only get Mint.
When running "update-grub", I get
Generating grub configuration file ... Found linux image: /boot/vmlinuz-3.16.0-38-generic Found initrd image: /boot/initrd.img-3.16.0-38-generic Found linux image: /boot/vmlinuz-3.13.0-67-generic Found initrd image: /boot/initrd.img-3.13.0-67-generic No volume groups found done