Moving from Mint 15 with Mate 1.6 to Ubuntu 12.04.4 LTS caused some grub issues on my Acer Aspire X1935. The installation seemed to go fine until I rebooted and then I came ub with the following screen – before even getting to a grub page.
error: file '/grub/i386-pc/normal.mod' not found. grub rescue>
I followed the details in the post below but the step that puzzled me was whether to mount the boot partition listed under fdisk -l i.e. the windows MBR or the linux root partition. Looking at the instructions and taking a bit of an educated guess of where grub sits I mounted the linux root partition and ran the grub-install command. That was the correct option! Grub installed, Ubuntu and Windows are now both bootable and all is good with the world.
Fix taken from this post: http://askubuntu.com/questions/266429/error-file-grub-i386-pc-normal-mod-not-found