I got this message the other day on rebooting my laptop (Dell Vostro 3550) and have similar messages in windows itself quite regularly. Had the laptop since september 2011 and these messages only started happening. The laptop was bought used but practically new with the remainder of the Dell warranty at the time (now expired). I'm assuming I've got a genuine power supply? I can't tell if it's 90W though. Assuming it's genuine, and I see no reason why it wouldn't be, particularly as the previous owner was under warranty, why would this message come up?