I finally got my key and followed the instructions for installing (search for "add features"...etc.). My key is accepted once entered and the download begins. After 30-60 seconds of processing, I get the error "Something went wrong, close this wizard and try again". It redirects you to a useless Microsoft help index.

Obviously I tried several times with no luck. Anyone faced and solved a similar issue. So far Win 8 Pro has behaved perfectly, until this.

Help please!