The test stays up, you can't go into the host machine to check your answers. I have heard of some testing centers that had trouble with this, but these are the places where people have been flunked. . . mainly because using the test-computer to check what the answer for a question is constitutes cheating. (Kind of like sneaking out of class during a history test in order to double-check an answer in your history book.) You're tested on what you bring with you to the exam: your knowledge, and nothing else. Even notepads and pens are given to you, they won't let you take your cellphone, pen, paper, or anything else with you into the testing area.
I had to empty all my pockets and place everything in a backpack and they locked the zipper. I was able to take it with me but it was locked. They did give me a dry erase marker and a pad to write on. Keeps the honest people honest.