When i am in the reply to sender window (Yahoo mail) and i press "to" or insert address bu

too bad

When i am in the reply to sender window (Yahoo mail) and i press "to" or insert address button nothing happenswindows installer

I'm not sure you are explaining correctly, but do this

someone writes you, click reply and than in the body part write what you want and hit send...............OHHH you are clicking "to". You have to click send.