This is not a driver issue. I get a valid IP address, I can ping the server.
I can map \\corename\ldmain to Z: using my credentials.
I can then copy z:\landesk\files\dosmenu.cfg to x:\ldclient\dosmenu.cfg
I can then run "PxeMenu.exe dosmenu.cfg" from x:\ldclient and the PXE menu appears correctly.
I've validated that the IIS permissions on the core do allow anonymous users to download the file and I've tested using IE from another PC that I can access it.
Running PxeMenuStart.cmd just returns the standard error.
Manually typing "sdclient /f /o /p=http://CORENAME/landesk/files/dosmenu.cfg" does not do anything. I've tried this with just the CORENAME and the fully qualified version of the CORENAME.