This isn't really going to help, but its something to try for your next install. I had troubles getting .Net 3.5 to install on a lot of the early builds, it wouldn't install from WU or from a mounted DVD/Image. So, I started adding it to the .WIM (with a few drivers) before I installed the OS, Its a pain if your doing a DVD install, but real easy with USB installs.
Yes, you can remove all pinned apps and remove extra space and create a nice compact Start menu. Even better with that in this build is the extra options to add icons on left hand side for Documents, Videos, Network, etc.
Yes i have a key, but i don't have an option to upgrade, the only "option" is searching in the Store for a new version of windows...
When you try it in cmd can u tell me the errors displayed when u run commands. Makes it easier to narrow down what's the problem
Can u put how exactly you typed the command. I'm thinking that you typed it wrong or one of the file paths that you specified is invalid.