Hi I take it that it is possible to record onto a USB drive rather than a HDD I understand that if you install a HDD then you can put the fan on. Does anyone know if you HAVE to use the fan? I am concerned about noise. In my PC I have my HDD inside an enclosure to keep the noise down and it has no fan on it and it had work for over 10 years. Does the TM need a fan for the hard drive or is it to cool the rest of the machine down? Finally, can you use the HDD without putting the fan on?