Rather than bringing up contraversial and "alleged" corruption on the name of the comforter (you strive at a gnat and swallow a camel), let us focus more on some the comforter's characteristics:
The comforter would abide IN US (John 14:16): Muhammed does not fit this category.
In John 14:17,26 it states that the comforter is the Spirit of Truth and the Holy Spirit. How then can Muhammed be the comforter when Muslims believers the Holy Spirit was the Angel Gabriel? The comforter is also suppose to glorify Jesus (John 16:14). The comforter is not to contradict the teachings of Christ in the gospels, yet Muhammed's teachings clearly contradict Jesus'. Also, the comforter (or Holy Spirit) dwelt among men AFTER Christ died. Christ had to die for the comforter to abide in men (John 7:39) but the Qu'ran teaches Christ did not die but someone who looked like Him (This brings up another question on how "Allah" can be so deceiving). If Christ did not die, then the comforter did not come.
Conclusion: Muhammed is not the comforter