I am assuming that you have Google Chrome. If you do, go to settings and you will see Search with the name of the search engine you are using. Click on the button and choose Google. That would probably make Cortana use Google instead of Bing.
So ever since I upgraded to windows 10 I have been getting this constant beeping type noise every couple minutes and I can't get it to stop unless I mute the computer completely. I've checked my notifications are all turned off and the only other thing I can think up is something with my Bluetooth because I know my computer has Bluetooth but for whatever reason right now it does't even show me Bluetooth as an option so I can't turn it off and I know I'm not popular enough to be getting that many emails. This noise is driving me crazy(er) and I can't get it to stop!
My other quick question is is there a way to change the default search browser for cortana from bing to google. I hate bing

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic