[Radek]

In the middle of a fight? No, it wasn't the computer, it was the game. You must be prepared for it all the time. This happens often: suddenly, the scene freezes. You can move your mouse pointer around but you cannot click anything. The keyboard does not work. Banging the keyboard results in beeping in the end because the input queue overflows: the keystrokes aren't processed by anything in the computer. Among others, any attempt to switch away from the game is futile. Sound seems to be okay.
You can do only one thing: hard reset by means of a button on your computer case.
It's the game who is guilty, not the hardware.