I can confirm that this does work.
im using windows 8.1 off my 500gb external HDD right now as you read n_n
if you need any help comment below
if you don't have a ISO image or a actual disk download an image from a torrent make sure its from a trusted uploader. then when you have ISO use a virtual disk drive application like Power ISO and mount it in a virtual drive.. next go through the prompts. and there its that easy!
problems with windows activate/product key let me know and I will send you a private tool.
remember to edit your bios for boot option.
warning: Updates may not work for you, turn off automatic updates and do one by one, if you don't have a true copy off windows and is a pirated version you wont be able to do all the updates and if you try to it may cause you to ruin your windows in this case just format it and redo the steps in the video 🙂