Mouse cursor not hiding!

here is my script as it says it wont hide

function Update () {
Cursor.visible = false; 

A few problems here.

First of all, did you attach this script to a game object in the hierarchy? If not, it will never run.

Second, don’t put Cursor.visible = false; in function Update() because this is called once per frame. You don’t need to keep setting it if you only need to do it once.

Put it in function Awake() or function Start().