so this must be a common problem. I had an old Windows machine with a disk that started to go bad (just some bad spots, corrupted files). So, I installed a new disk beside the old one and put Mint 17 on it. grub-mkconfig picked everything up. Life was good.
Then one day, the old windows disk fully died, click, click. So, I unplugged both power and data cables from it, ran update-grub. HOWEVER... I'm still seeing old stuff from the unplugged partition in my grub boot menu (Dell partition recovery, etc.). So, obviously, I've left a step or two out. What?
sudo update-grub
?