My new amd64 system's CPU fan went off everytime I boot the pc. The fan would work only for around 10 seconds after booting before going off completely. :confused:

It's probably cool'n'quiet (http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_9485_9487%5E10272,00.html) working. It shouldn't be a problem as long as it turns back on when your computer is doing some serious work (encoding, gaming, etc.).