A JavaScript.NET script for adding Japanese language to Modern.IE 32bit Windows 8 (MIT License)

addLang.js

import System.Windows.Automation;
import System.Threading;
import System.Diagnostics; 

Process.Start("C:\\Windows\\system32\\control.exe");

function waitForTopLevelWindowWithName(name) {
  var cond = new PropertyCondition(AutomationElement.NameProperty, name);
  while (true) {
    var win = AutomationElement.RootElement.FindFirst(TreeScope.Children, cond);
    if (win) {
      return win;
    }
    Thread.Sleep(100);
  }
}

function waitFindFirstDescendant(elem, cond) {
  while (true) {
    var match = elem.FindFirst(TreeScope.Descendants, cond);
    if (match) {
      return match;
    }
    Thread.Sleep(100);
  }
}

var cPanelWin = waitForTopLevelWindowWithName("Control Panel");

var addLangLinkCond = new AndCondition(
  new PropertyCondition(AutomationElement.AutomationIdProperty, "tasklink") ,
  new PropertyCondition(AutomationElement.NameProperty, "Add a language") 
);
var addLangLink = waitFindFirstDescendant(cPanelWin, addLangLinkCond);
addLangLink.GetCurrentPattern(InvokePattern.Pattern).Invoke();

var langWin = waitForTopLevelWindowWithName("Language");

var addLangBtnCond = new PropertyCondition(AutomationElement.AutomationIdProperty, "AddALanguageButton_TB")
var addLangBtn = waitFindFirstDescendant(langWin, addLangBtnCond);
addLangBtn.GetCurrentPattern(InvokePattern.Pattern).Invoke();

var addLangWin = waitForTopLevelWindowWithName("Add languages");

var japaneseListItemCond = new AndCondition(
  new PropertyCondition(AutomationElement.LocalizedControlTypeProperty, "list item") ,
  new PropertyCondition(AutomationElement.NameProperty, "Japanese") 
);
var japaneseListItem = waitFindFirstDescendant(langWin, japaneseListItemCond);
japaneseListItem.GetCurrentPattern(InvokePattern.Pattern).Invoke();

var addBtnCond = new PropertyCondition(AutomationElement.AutomationIdProperty, "AddToLanguageList")
var addBtn = waitFindFirstDescendant(addLangWin, addBtnCond);
addBtn.GetCurrentPattern(InvokePattern.Pattern).Invoke();

var langWin = waitForTopLevelWindowWithName("Language");
var jaTextCond = new AndCondition(
  new PropertyCondition(AutomationElement.LocalizedControlTypeProperty, "text") ,
  new PropertyCondition(AutomationElement.NameProperty, "ja") 
);
var jaText = waitFindFirstDescendant(langWin, jaTextCond);
var jaListItem = TreeWalker.ControlViewWalker.GetParent(jaText);
jaListItem.GetCurrentPattern(InvokePattern.Pattern).Invoke();

var moveUpBtnCond = new PropertyCondition(AutomationElement.AutomationIdProperty, "MoveUpButton_TB")
var moveUpBtn = waitFindFirstDescendant(langWin, moveUpBtnCond);
moveUpBtn.GetCurrentPattern(InvokePattern.Pattern).Invoke();

var closeBtnCond = new PropertyCondition(AutomationElement.AutomationIdProperty, "Close")
var closeBtn = waitFindFirstDescendant(langWin, closeBtnCond);
closeBtn.GetCurrentPattern(InvokePattern.Pattern).Invoke();

build.cmd

jsc /lib:C:\Windows\Microsoft.NET\Framework\v4.0.30319\WPF /reference:UIAutomationClient.dll;UIAutomationTypes.dll addLang.js