essentially you need to mount both your boot.wim + install.wim + DVD\Sources folder and resource edit every instance of, spwizimg.dll, imageres.dll with the image you like. spwizimg.dll is resource number 517,518 and those directly affect the logo while installing. Best bet is to alter one copy with a resource hack tool, and (take ownership first) replace the three copies you find (one in boot.wim, install.wim, and on the DVD\Sources folder) imageres.dll is the "logon" screen (seen only at first boot). So I think you might only need to edit the one inside install.wim. Also there is a registry hack to change logon screen, that can do this without editing the imageres.dll