The Ubuntu 6.10 grub menu.lst file and you...

Did you recently upgrade your Ubuntu install to 6.10 (Edgy)?

If yes: After you upgraded, was your dual-boot windows option mysteriously missing from the grub boot list?

If yes: Did you fix it?

If no: Do the following.

Log into your Ubuntu system and add (as root) the following to your /boot/grub/menu.list file, at the bottom, then reboot:

title  Microsoft Windows
root  (hd0,0)
savedefault
makeactive
chainloader +1

Read more about this fix here.

This fixed mine. Phew.