I looked at that boot repair tool, but it's for ubuntu and I'm running Win7, I do have ubuntu but it's on the disk I'm trying to fix!!
Boot repair is an iso and will boot directly from a usb stick. It provides its own linux os on the usb. I always keep a usb with tools on it for problems like this. Download yumi (here
) and then download the boot disk iso and load it through yumi. Reboot to usb, choose boot repair 64bit and away you go.