How to get the free disk space of a remote machine using c#?

//Check whether the Drive Fetched from App.Config exists in the system
      if (Environment.SystemDirectory.Contains(DBDriveName) == true)
      {
       //Fetch the Drive Name exists with that in the App.Config and see there is enough space to create DB Back Up
       foreach (DriveInfo drivename in DriveInfo.GetDrives())
       {

               //Fetching the free space of the drive from App.Config if existing and  obtaining the same in MB
               if (drivename.IsReady && drivename.Name == DBDriveName)
               {
                   TotalDiskFreeSpace = drivename.TotalFreeSpace / (1024 * 1024);
               }
        }



   }
   else
   {

       //Pass the msg if drive is not exisiting fetched from App.Config
       DbBackUpStatus = "Drive doesn't Exist";

   }