[kwlug-disc] mbr / grub2 hosed - easiest fix?

[unsolicited]

I'm dual booting. Along the way I've hosed grub2 / booting / partition 
bootloader.

Data's all there, just no boot.

Getting Win 7 to boot again, on a laptop with no cd or floppy is just 
STUPID. All my tools, cds, diskettes, etc., fail because they don't 
know / load usb drivers. e.g. a diskette ramdrive from a cd load works 
fine - but doesn't have usb drivers loaded to get back to the cd it 
came from. <sigh>

Once I'm over that, anyone run into the restore grub2 problem and 
solved it concisely?

e.g. I can chroot /dev/sda3, and grub-install, and grub2 tries real 
hard ... but it didn't pick up it's (old) menu when it grub-installed. 
Or regenerate it either. (Regeneration being problematic in a 
chroot'ed environment.) So grub starts, but it's got no menu or 
configuration. Darned if I can't get the UUID references right, from 
memory.

Anyone been through this / got a good web page?

Thanks.