setPropertyValue does not work with win32_volume?

here is my code, basically, i want to assign drive letter "H“ to a removable usb drive
but when I try to set value for drive letter, there is no exception or error, nth happens.
problem seems to be following line, but i couldnt find out how to fix it.
mo.SetPropertyValue("DriveLetter","H:");

im using win7 and tested with administrator previllage when running debug.
can someone please help?

public static void Main(string[] args)
        {
            RetrieveDiskInfo_DriveLetter rdd = new RetrieveDiskInfo_DriveLetter();
  ManagementClass mc = new ManagementClass("Win32_Volume");
            ManagementObjectCollection moc =mc.GetInstances();
           
            if(moc.Count!=0)
            {  
           try{
           
            foreach (ManagementObject mo in moc)
                {
              
                    if (mo["DriveType"].ToString() == "2")
                       {
                            Console.WriteLine(mo["Drivetype"].ToString());
                            Console.WriteLine(mo["DeviceID"].ToString());
                                 mo.SetPropertyValue("DriveLetter","H:");
                       }
                    
                  }
             }
            catch (Exception ex)
               {
                            Console.WriteLine(ex.ToString());

               }
                
            
        }
      }