Hey thanks for the quick reply,
From other searching I now think my problem is related to lack of a NIC driver in the winpe boot image. One boot image which I've used in the past successfully has a driver, now I'm trying to PXE boot on 64bit hardware and the 64bit boot winpe image does not have a NIC driver included, and when the task sequence hangs, I hit F8 for command prompt support, type IPCONFIG and I get nothing, so yeah, I think it needs a NIC driver - but, I'm trying to add one and I keep getting an error:
Failed to insert OSD binaries into the WIM file
seen that before? I've tried a number of different drivers. Is the WIM file locked or something? is there some step I'm missing?