Windows back-compatibility support has its limits these days. The advertised vehicle for old enterprise XP apps that you just can't upgrade is "Windows XP Mode

Windows back-compatibility support has its limits these days. The advertised vehicle for old enterprise XP apps that you just can't upgrade is "Windows XP Mode" (duckduckgo it), which is XP itself running under Virtual PC. (Yes, "well behaved" XP apps are supposed to be able to run on Windows 7 natively, but the mere existence of this other thing is a concession that many apps of interest are not that well behaved.) The same strategy could be used to maintain back-compatibility across much more drastic transitions, if they were of a mood to make them.