I was wondering if anyone could help me identify this whirring/whining noise coming from my '05 freestyle. Sound emanates from the front of the car whenever it is in motion, and I'm pretty sure it's not the transmission, as the noise continues even when the car is in neutral and moving (but not sitting idly). Could it be related to the front differential?

 

I would try running the engine very briefly with the belt(s) removed to see if the noise disapears. Pulleys, alternators, water and power steering pumps then could be ruled out if the noise continues. A fluid check of the transmission should be done.A transmission can create abnormal noises even when the vehicle is not in motion.I can't see it being from the differential or a wheel bearing if the noise can be heard when the vehicle is stationary.
A mechanics stethoscope can be useful for locating unusual noises.