Perfect performance all week, today "Dolphin not working properly"

[Terrornaught]

Put Dolphin on my new computer on saturday, every game I've tried has worked pretty much perfect. Now today I start getting the "Dolphin not working message, the longest I can play for is 20 minutes sometimes only 5. I have deleted it reinstalled it, tested different games and no luck. My PC is cool and the cpu usage maxes out at about 50%. I do not understand why this has suddenly started happening.