My Mac OS X 10.5 (Leopard) first intel iMac, was recently defragged and I tried to do "slim down" feature in Drive Genius software. I did use the feature that removed non-intel data. I am wondering if that affected the start up, and how do I resolve this issue? I was planning to put in a new hard drive since the current one has only 2 GB memory. The computer was running very, very slowly and Photoshop (I am a photographer) was freezing the entire computer (as of today). I am wondering about virus issues. When I went to defrag, I found I had only 13 GB of space left on my hard drive. My photos are stored on external drives. The last time I checked, I had about 1/3 space left. I don't believe I've added anything new to take up that much room. I got through the defragging and slimming just fine, removed some photos, and then restarted the machine so I could read the current space available. The computer now will not stay started up. It starts, gets to the moving wheel, and then shuts down.