@ahuggingsam@mastodon.art I only know of this for Windows XP; the "XP Mode" in Vista (and 7?) was basically just a preinstalled clean VM image of a Windows XP install, that you could download from Microsoft directly and also just extract and run in normal VM software.

Don't know if something equivalent exists for other Windows versions, but I do believe that Microsoft at least offers (free) downloads of their current OS versions from their site specifically for testing compatibility. Don't know if they're preinstalled though.