After installing a new system board, the system pauses for about 90 seconds with the following on the screen
VIA RHINE II FAST ETHERNET
CLIENT MAC ADDR:00 11 09 A7 F2 6D GUID 00000000-0000-0000-000000000000
DHCP ......
The the following is displayed, before the system then finally boots correctly
PXE-E52 - NO BOOT FILE NAME RECD
PXF-MOF:EXITING INTEL PXE ROW

Any ideas, XP seems to run OK

Did you run a Clean Install of XP?

If not you need to.