All,
I have received a question today: Does SetupBuilder 2025 still support “legacy” Windows versions?
Well, SetupBuilder 2025 supports all kinds of new technologies now. Trusted signing, thumb-drive EV and OV certificates, Windows 11 and Server 2025, built-in ARM64 enhancements, .NET 9, etc. So that is really an interesting question.
Pictures tell more than a thousand words. This is an installer created with SetupBuilder 2025 running on Windows 95. IMO, Win95 is a legacy operation system 
Check the KERNEL32.DLL date: it’s from August 1996!!! Nearly 30 years ago (good old times ).
So the short answer is, yes, SetupBuilder 2025 still supports legacy Windows operating systems.
Friedrich