We still don't know from those pictures what your max temps during the stress test were. Your max CPU usage is only 27% in what you show in the pics. XTU does not keep a record of peak temps but only reports temps real time. Besides, it's a very whimpy stress test to begin with.
There is nothing to know about Prime95 and how it works. You download it, install it and launch it. When it launches choose the stress test option and "blend" options in the popup windows, which I think are already chosen by default. It will then start to put your computer through a demanding set of computations which will put it under heavy load. But then you should also have CoreTemp or RealTemp open on the screen in order to monitor the temps and voltages.
I get the definite impression this is all very new to you.
Edit: By the way, unlike XTU the other stress tests we have recommended do not provide tools to overclock your CPU and memory so if that is what you mean by saying "I don't know how it works" with regard to Prime95 you need to know Prime95 is simply a stress tester.
Furthermore, until we can establish that your cooling is doing it's job, you should not attempt to overclock.