Why my HTC One M8 settings menu doesn't have Software Update?

I'm using android 4.4.4 in my HTC One_M8. But I can't find Software Update in Settings->About->Software Information menu. There supposed to a menu Software Update in that section. Can anybody help why I'm not seeing that menu. Thanks.
Screenshot:
s3.postimg.org/fsjx79teb/Screenshot_2015_08_09_12_43_53_1.png