...because SL requires 1 Gig, and I only had 512 MB. I'm shocked at how much smoother this machine is running. It almost feels brand new; very peppy, smooth, my applications pop right open. The best part about it is, I got it from some place called Data Memory Systems, and with overnight shipping it only cost me 27 bucks. Best 27 bucks I think I've ever spent. It's a good thing, too. I was starting to get pretty irritated with this machine.