My Studio XPS 9100 desktop computer shuts down completely without warning. Got it new in 2011 and this problem only started a month or so ago. Dust/dirt NOT the problem. Cleaned it 27 June 2015. Current problem shutting down never started until 06 Aug. 2015 so no connection to my cleaning and I do use computer almost every day. I just ran Dell's
<ADMIN NOTE: Service tag removed per privacy policy>
and didn't find any problem.