Hello, I have a 15 inch Macbook Pro that I got in November of last year, and the past 2 months or so it has been lagging like crazy. Just doing simple tasks, like typing this message brings up the apple working wheel. I have 4 gig of ram, and i just reinstalled the operating system. Could there be something wrong with my hard drive that is causing the operating system to run slow? Any suggestions? Or should i just call up apple and let them try and figure it out?