This seems to be the most simple thing, but it isn't even a function! I ask Cortana to remind me to buy milk tomorrow at 3pm. She sets up the reminder. Great!! 10 minutes later my wife says, "I bought milk." Ok.... "Hey Cortana, cancel my 3pm reminder tomorrow." *Cortana opens up the Bing web browser*. WHY??? Why do you make me go into Cortana's notepad and cancel the reminder manually? She is supposed to be my personal assistant! Can you imagine an executive director taking his assistant's notepad and scratching appointments off? Sheesh!!