public static void InitiateInstanceWithDir(string installDir)
 {
     if (installDir == null)
     {
         throw new ArgumentException("installDir cannot be empty or null!");
     }
     if (_instance == null)
     {
         _instance = new SasManager(installDir);
     }
     else
     {
         _instance.SetSteamInstallDir(installDir);
     }
 }
 private void askUserForSteamLocation()
 {
     //No steam directory in Settings, let's find 'em!
     if (Properties.Settings.Default.steamInstallDir == String.Empty)
     {
         //Run this on first start
         string installDir = UserInteraction.selectSteamDirectory(@"C:\Program Files (x86)\Steam");
         if (installDir == null)
         {
             MessageBox.Show(
                 "You cannot use SteamAccountSwitcher without selecting your Steam.exe. Program will close now.",
                 "Steam missing", MessageBoxButton.OK, MessageBoxImage.Error);
             Close();
         }
         else
         {
             Properties.Settings.Default.steamInstallDir = installDir;
             SasManager.InitiateInstanceWithDir(installDir);
         }
     }
 }