You're not free to make copies without the license. You are free to make copies with the license, because that's what the license granted you permission to do. You aren't free to do so without preserving the license, because you don't have a license to do that and that's copyright infringement.
You aren't required to publicly release derivative works or their source, simply because the license grants you the ability to produce derivative works (provided you keep the copyright information intact) without publicly releasing them. You are required to keep the copyright information intact, because the license does not grant you permission to produce derivative works if you do not.
The requirement to keep the copyright information attached is simply not connected to your choice to distribute it or not. It's a requirement any time you make a copy or make a derivative work, even if you're only making that copy or derivative work for yourself.
That was my understanding. If removing the license is a breach of terms, therefore the GPL now fails to apply, then it falls back to default copyright laws. And no one would argue copying MS Windows 'internally' is fine.
You're not free to make copies without the license. You are free to make copies with the license, because that's what the license granted you permission to do. You aren't free to do so without preserving the license, because you don't have a license to do that and that's copyright infringement.
You aren't required to publicly release derivative works or their source, simply because the license grants you the ability to produce derivative works (provided you keep the copyright information intact) without publicly releasing them. You are required to keep the copyright information intact, because the license does not grant you permission to produce derivative works if you do not.
The requirement to keep the copyright information attached is simply not connected to your choice to distribute it or not. It's a requirement any time you make a copy or make a derivative work, even if you're only making that copy or derivative work for yourself.