I think a quick manual edit to GRUB should fix it bro.
Look in boot/grub/ for the grub.cfg file. That should have all your available boot options. If you see the option for windows, make sure it isn't commented out, usually with a # preceding the line.
Here's a pretty good guide. The OP covered a lot of options.
Just as an aside - this is why I always use the bios to switch between OSes.
Give me a bootloader to play with and I will absolutely murder it.