Unexpected Shutdown And Then Restart, Upon Mouse Scrolling

I'm in the process of scrolling the page using mouse wheel (either browser, or microsoft word document, etc) the screen blinks for a fraction of second, and the whole system shuts down as if somebody pulled the plug out, and then immediately restarts showing dialogue of whether I want to start windows normally or in the safe mode.

I have looked in the event logs but the only thing it tells me there is that there was an unexpected shutdown. The same in that reliability place.

how I would diagnose it? I cannot replicate it at will, as it only happens occasionally when scrolling, at other times scrolling is fine and does not produce this result. The system is Windows 7 enterprise 64bit, the mouse is Microsoft bluetrack technology