Deploying Server 2003 with MDT 2008 on Hyper-V server.
Issue : You will find machine boot fine with PE 2.0 and connect to the deploy share but after deploying the 2003 OS. At the first boot you will find the machine does not connect back to the deployshare.
Resolve : Windows 2003 does not hold the driver for Hyper-V Legacy NIC in Windows. So you need to extract from one of the below source and add it.
Virtual Machine detects the Emulated NIC as : Intel 21140-Based PCI Fast Ethernet Adapter (Emulated). This driver is part of Windows 2008/Vista already or a Windows PE 2.0 stored under %systemroot%\System32\DriverStore\FileRepository\dc21x4vm.inf_7d8c6569
Extract this driver from one of the above source and then add it to MDT Out-of-Box driver section and then update your network deploy point.