when you put on the hsf, hook the side WITHOUT the ridge sticking up first. then push down the side with the ridge, using a flathead screwdriver. you have to push down REALLY hard. if it looks like it doesnt go out far enough (if it cant hook over other clip-dealie), then you should push out a little bit with the screwdriver too. just dont let the screwdriver slip out and break teh mobo!