> If we're going to launch cmd.exe, I'd prefer to only do that in the 
> platform module and not the sys function. Nothing in sys should 
> start a subprocess (if we can at all avoid it).

In that case, would you want to deprecate sys.getwindowsversion().platform_version?

platform._syscmd_ver() is already implemented to parse the output of CMD's VER command. The result has to be post-processed because the regex isn't as exact as it could be. It supports versions back to Windows 2000, which returned "Microsoft Windows 2000 [Version maj.min.build]". Starting with Windows Vista up to early versions of Windows 10, the format is "Microsoft Windows [Version maj.min.build]". In more recent versions of Windows 10, it includes the update build revision number -- "Microsoft Windows [Version maj.min.build.ubr]".