Hi! I'm about to upgrade to 14.04. I have dual boot with windows 8.1. I can't use the standard upgrade tool because my internet connection is too unreliable and the tool crashes out every time the connection is lost - I keep getting errors and having to start again. So I'm using Transmission to torrent the ISO file.
My question is, how do I upgrade from an ISO on my harddrive, making sure grub dual boot isn't damaged? Last time I upgraded I lost windows boot option and had to use boot repair to get it back. This was easy and worked well but I'd prefer to get it right first time!
I've hunted for information but most posts seem to be related to fixing grub after upgrade, rather than getting it right in the first place - but point me to the correct posts please if you know of any!
Step-by-step-for-blithering-idiot instructions, please