grub error with dual boot HP notebook

[Noah Tellin]

I have an interesting (and ANNOYING) problem with a laptop that I
recently installed Linux Mint on alongside Windows 7. Less than two
hours after telling a friend that I was experiencing no more tech
troubles, my HP 620 failed to boot, only getting as far as grub rescue
mode.

The message is:

error: file 'boot/grub/i386-pc/crypto.mod' not found.
Entering rescue mode....
grub rescue>


The two operating systems are Windows 7 Home Premium and Linux Mint 17.

The hardware is an HP 620 notebook purchased in 2011. It does not have UEFI.

This seems to be a very similar problem with someone using Tumbleweed
a year or so ago.

I don't have a boot DVD with me, but will give it a try when I get home.

Anybody have this unpleasant experience or encounter something
similar? Any suggestions?