Editing Grub - "no such file or directory found"

"sudo gedit /etc/default/grub

then edit the line -
GRUB_DEFAULT=0
to
GRUB_DEFAULT=4 (assuming you have only 2 os 1 ubuntu another xp / vista / 7)

save the file, then run

sudo update-grub"

"I believe the file containing the menu is now grub.cfg

When I changed it, I just edited it (and ignored the message NOT to do so).

I can see it in the listing you provided. I think you want to put the entry for Windows 7 first in the menu.

I hesitate to say more, because I don't have a Windows entry in my grub.cfg, and it would be dangerous for me to speculate on what to do next."