I downloaded a big file of .Net 3.5 SP1.
Now when I try to install it on Windows Server 2012, I get the following screenshot:
Now this is a loop. When I try to install from Server Manager, I get installation cannot be done. It needs the installation disk.
Does that mean I can't install at all without the installation disk in presence?
Your WSUS server is probobly getting in the way, or you just can't reach the Microsoft update site.
Follow these directions. "Specify settings for optional component installation and component repair" worked for me.