lockup

I'm still only running windows defender as requested in previous thread and suddenly the crashes have started again. When it triggers, its either a BSOD or total lockup of the system.

I don't know what in the world is going on but in the last 24hrs I've had 3 HARD lockups, a bsod ( last night while idle ) , Camtastia Studio crashing , Chrome sites saying flash is not installed, another site on IE said java was not installed. All of this was working fine just the other day...