How do I force close pop-ups or Safari when windows and dialog boxes open up unannounced? Twice today I went to sites (different news sites) that popped open dialog boxes for Mackeeper. I tried to close the windows without responding to the questions and could not find the proper way to do this. I ended up holding down the power button to reboot. I do have block pop-up windows selected in my Safari preferences, but developers must have a way around that already.