I ordered my first Mac (Yes, after 12 yrs with PC, this is my first Mac, 17 MBP C2D 2G/160G/Glossy) on Oct. 30th. I got it this Monday(Nov. 20th). Yesterday, I began to install boot camp and WinXP, everything looks fine. After I finished installation and transfered all my stuff. last night, this happened: Just turn on the MBP and let it idle, the temp will be 45C at most, but, the fan speed up and reach the MAX speed and stay there. So, it sounds like a jet. I spend 3 hours and can not let the fan slow down...finally, I run the hardware test. It gave out error code: 4SNS/1/40000000 : Th1H So, now, i need send it back and wait for the replacement---just before thanksgiving. Do not know if anyone here have similiar case as mine.