Rooted after one month. And the reason for that is simply lack of knowledge and experience.
So if you you cannot get user/root - try harder and learn more. Take a break (I did four or five different boxes meanwhile).
Read the tutorials for the exploiting Windows, in the end you find out that this box is not the rocket science.
BTW I can see on the “Page info” of the web this:
Have I visited this website prior to today? Yes, 1 491 times 
So be patient and GL, I go for beer…or three:)