About John 14:16, the verse never mentiones that the comforter is Holy Spirit. if it is a Christian interpretation of the verse (John 14:16) I dont know about that, but Muslims say that this comforter is Mohamed(pbuh).
It is written:John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
God Bless!