Could you please how to disable/enable windows from x button. I tried to set property this ControlBox=false but this hides all of those sizing buttons. Not just the X. Then i tried to use this below code through C# code but i got the error that can't be override method CreateParams. 

private const int CP_NOCLOSE_BUTTON = 0x200;
protected override CreateParams CreateParams
{
    get
    {
       CreateParams myCp = base.CreateParams;
       myCp.ClassStyle = myCp.ClassStyle | CP_NOCLOSE_BUTTON ;
       return myCp;
    }
}

Please anyone help me to resolve the issue.

Thanks