For the loud fan issue, re-run the FRU. If the fans are still loud after that, check the System Event Log (SEL) - it will tell you if you accidentally have a fan plugged into the wrong header.
For the pauses in Windows, try updating your network card driver. That pause is caused by some background task, and that's one of the more common ones.
Okay, just installed Windows 2008R2 SP1 once again and the system even freezes during the installation....just before the first reboot..and then again where Windows prepares for the first start. Sorry, but this can´t be a normal behaviour...
Okay, you were right, installing the NIC drivers helped a lot, the machine doesn´t freeze anymore.
But, another thing, why does Windows show me 48GB of RAM installed but only 32 usable?
Thanks a lot