Also, a short suggestion, the nexus can be put into bootloader via terminal commands.
For those of you having problems getting it to work, feel free to email me and I can attempt at helping. What I'd advise is that the folder you're pulling the files from be as short of a path as possible, ie as close to the hdd as you like. It makes for fewer entries. Also, name the folder simply and W/ out spaces. Last but not least, having the folder located where there isn't much else to wade through, or fewer files so its easier to determine that your in the right folder.
Just my .02
Sent from my Galactic Unicorn!