A real pain isn't it? I called Toshiba customer service and they told me that the Google cast/Chromecast setup screen appearing upon turning on the TV, and worse, changing your input to Google cast instead of your desired HDMI input, could NOT BE DISABLED. Only after I relented and setup the TV's WiFi and paired with my iPhone did that Google cast setup screen stop coming up and the TV retain the last selected HDMI input. I was not warned about this when I purchased the TV and was madder than a wet hen when I encountered this problem.