There's likely good bit of business to be had for 3rd party supported back-ports of security updates and maybe even the new NET framework and its updates. IDK though if MS has somehow restricted companies from doing such without separate agreement. There's certainly some cases where Vista and newer are not good because of say poor support for hardware accelerated GDI drivers. Or maybe there's some industrial/scientific thing that uses game port. Some issues can be worked around or apps updated but if there was enough demand for backports of patches and such, the cost of that service could be low enough to be sensible alternative to working around app specific issues.