Due to incompatibilities I needed a way to detect the version of Windows my game was running on. Sys.systemName() helpfully returns "Windows" and nothing more, so I had to get creative.

WindowsVersion.hx

package com.grapefrukt.utils;

/**
 * Retrieves the version of Windows the application is running under
 * @author Martin Jonasson, m@grapefrukt.com
 */
class WindowsVersion {

	private static var inited:Bool = false;
	private static var _major:Int = 0;
	private static var _minor:Int = 0;
	
	public static var major(get, never):Int;
	public static var minor(get, never):Int;
	public static var isWindows(get, never):Bool;
	
	private static function init() {
		inited = true;
		#if cpp		
		// if we're not on windows, this won't work at all
		if (!isWindows) return;
		
		// call out to cmd.exe to get the version (it's listed when it starts up)
		var process = new sys.io.Process(Sys.getEnv("windir") + '\\system32\\cmd.exe', []);
		var output = "";
		
		// try to read the stdout, this crashes if there's nothing to read, hence the try/catch
		try {
			output = process.stdout.readLine();
		} catch (e:Dynamic) {
			// call failed, not much to do about it
		}
		
		// regex out the values
		var r = ~/Version (\d+)\.(\d+)/g;
		if (r.match(output)) {
			_major = Std.parseInt(r.matched(1));
			_minor = Std.parseInt(r.matched(2));
		}
		
		// finally, close the process, it should be closed already, but just to make sure
		process.close();
		#end
	}
	
	private static function get_major() {
		if (!inited) init();
		return _major;
	}
	
	private static function get_minor() {
		if (!inited) init();
		return _minor;
	}
	
	private static function get_isWindows() {
		return Sys.systemName() == "Windows";
	}
	
}