I just purchased my Imac 2 days ago, I am new to Mac. I was trying to install Iwork09, and had the following programs on : Itunes (music playing), 2 USB flash memory, Safari. And the system just slowed down. There was no response, so what I did was to just turn the power off and restart. Everything ran smoothly again... When I get stuck how should I turn off the MAC? I trying Force Quit, but it wouldn't work... Also I like running computer very simple with no clutter, how do I change the start up programs? Any maintanence I need to do so the system runs smoothly and fast?