I agree, before starting the test you need to make sure that you are not going to be disturbed.  For me I studied all the material and then went to my office and closed the door.

I agree! I found that the best way to complete the training was to stay a little earlier/later to complete a little at a time. Trying to complete the training during office hours was next to impossible. Given all my day-to-day responsibilities making time at the end of the day was best. Also, Fridays are good days to train as well. There's less traffic in our office on those days as well.