Thank you for the post. What you can do is try to reflash the bootagent , download preboot.exe at Download Intel® Ethernet Connections Boot Utility, Preboot images, and EFI Drivers
Run and extract the fiel.
copy the bootutil.exe into a bootable dos disk.
Go to dos prompt to excute the following command:e.g
C:>bootutil to display the list of NIC on your system
if GT desktop is define as NIC 1,then run the ff command
c:>bootutil -NIC=1 -up=pxe
Please refer to this site for additonal bootutil command info: