Most likely PXE server was not installed, Try to run the installed again under custom install.
There you can specify also to install PXE server on the GSS server
https://www.youtube.com/watch?v=mR5e0q37GXc&list=PL8--xIUzrrzTpAcjmX5mA88OnJibj1glx&index=2
I personally like the custom install much more as it gives more info while installing