Maria, I would like to add some info for situation. In fact problem was not solved as I described above. In a few weeks it arize once more and freezes became really awfull. I updated Paralells to ver 15 but it doesn't help. As I see, some process of Windows trying to connect to net about 15-20 sec and during this process Windows stopped. I prepared another Virtual maschine and install only some necessary programs. It works fine. Old VM could be executed with the same problem as earlier. As I see, problem is in some incorrect Windows service.