If you own an IMAC you probably did not know that it need to be cleaned inside. Everyday dirt builds up on the fans inside and restricts the airflow. This promotes overheating and stress on components. Especially the Hard Drive and Graphics Card. Don't let this continue. Check the back of your IMAC above where the power cord is. There are vents there. If they are starting to get furry its time to clean it. See pictures for examples. Dont take a vacume or use your hand and try to remove it, it will make things worse. You want a certified technician to take your IMAC apart as it very delicate inside. I can't tell you how many times people have tried this on thier own only to have to replace the IMAC because they damaged it. No Appointment necessary. About a 2 hour turn around time. IMacs before 2011 $60, 2012+ $100. Computerconcepts.ca 1902 Robertson Rd Bells Corners 613-596-2861