the scenario is that we have an automated build environment for Windows, Linux and VMWare ESX using pxelinux off one tftp/pxe server. The default option we have is to boot WinPE3 after 60 seconds. I need to be able to instruct selected hosts to boot a different WinPE3 environment automatically, which can be done by created a MAC answer file on the in the pxelinux.cfg folder. This needs to be a zero touch environment - so users selecting a different WIM file from the bcd menu is not an option. This seems to be what lolan also acheived with the binary editing of the bootmgr.exe. I'll check out the post you included to see if that helps me.