As mentioned above, my PC keeps crashing or hangs. I have recently started again with minecraft. About two three days ran it well, then he hung to the middle of the play, and I had to do a hard shutdown. I have a precaution to factory settings reset to and avoid the PC again viruses similar. Then I have nothing downloaded as Minecraft, Minecraft server Hamachi and openoffice. While it runs longer good but he is still hanging and crashes. I've updated all the drivers and with Norton a full system check for viruses made of revealed nothing. So it is not a virus. My PC is no way slow old cucumber. It is already some years old (Windows 7) but was always a good PC with great performance. I have freed the PC from dust recently. What could be so.