Hi,
Your problem either lies in the PXE boot process, or within the automation environment. To narrow down, can you detail what happens when your server PXE boots. For example, is it getting as far as downloading your preconfigured DOS/Linux/WinPE image? If not, you need to configure your PXE Boot environment from within the "PXE Configuration Utility"
If automation is successfully downloading, check that the account you've used in the automation environment has full permissions on the express share folders eXpress\Images, eXpress\Temp, eXpress\LOG.
Kind Regards,
Ian./