dual boot problem

[Ralph Pichie]

After dozens of successful dual boots with Ubuntu and other
Debian-derived distros (3D!) I've encountered my first unbootable
machine tonight, with the little-loved error message "Missing
operating system".

I've got Windows 7 back now with the boot flag on the primary
partition device, but no grub menu. I really wanted to try Vector, but
I'm loathe to waste more time, as this is a new laptop that needs to
be productive.

Would it be better to try to fix the boot loader directly or try to do
an Ubuntu install with or over Vector to fix it?