I just came across this website: https://winworldpc.com/library/operating-systems.
It’s a treasure of old or never-released versions of Windows, from 1.0 to Longhorn, giving some history and background information for each. Windows antiquarians will have a field day paging through this site!
Old versions of other operating systems (Apple, Linux, DOS and CP/M) are also available.
This may get me to start exploring virtual machine software, to take Longhorn for a spin. ๐