Hi
Since last week, my wife started playing with me.
She has an I5 4570 and a GTX 750TI.

I will be soon able to test this issue with the GTX 660 and with the 750Ti as Physikcard.

Her problem was everytime we play, that sudden she falls back on Desktop. The game doesn't seem to crash as window works normaly, no message that DayZ.exe is not responding or so what. Then she reopen the Window from the Taskbar, the Mouse changes his form in DayZ Mouse, but she continues seeing windows.

When she turns the mouse, I can see her ingame turning around and shooting by LMC, but she only sees Windows. the only way is to Ctrl + Alt + Delete, kill DayZ and restart.

I don't have this problems with an GTX780 SLI. It happens to switch me to Desktop very often, but I can rejoin easily the game.