KACE Product Support

I've had this happen a couple of times before and it ended up being a bad hard drive.

Check the switch port this machine is plugged into to see if you are getting a lot of errors, you should also be alse to see what speed is negotiated from the switch end and if there is a mismatch.  Try another model on same wire if problem goes away may be your PXE boot. 

Your PXE boot may not have the proper driver compiled in it and it is negotiating the wrong nic speed.  If that is the problem add the driver to the KBE driver store and recomplie your boot environment.