I too my Alum 13' Macbook 2.4 ghz to a local computer shop to install windows XP SP3 on my macbook. My father has the 2.0 ghz and his works with absolutely no problems. When windows xp was working it would take at least 5 min to start up until it took me to the desktop screen. Most of the booting time the screen would be completely black. One day I wanted to boot up windows on my macbook and it stayed on the black screen for a very long time. It was unusual so I restarted the macbook and left the macbook to boot up windows for one hour. The screen remained black. I could hear the fan to be a lot louder. I am not sure if its a virus or not. I am able to boot up windows fine in the safe mode. I took it back to the technician if he could fix it and he has never encountered a problem like this before. He has installed numerous Windows on macbooks and recommended me to take it to Apple to do a hardware check. I really dont want it to take to Apple because I am at school and I need my macbook at all times.