You may need to update or configure the controller - skip ahead to Set Up Your Controller Via The Xbox Accessories App. You will know if you were successful if the Xbox One controller power light goes solid. The Xbox One controller should hopefully appear in the list after a few seconds - choose to pair to it.
From the screen that appears select "Bluetooth". There is a workaround - hit the + symbol next to "Add Bluetooth or other device" on the "Bluetooth and over devices Settings" page. However in our testing we struggled to get the PC to find the controller. The controller's power light should flash quicker, and then "Xbox Wireless Controller" should appear in the list of devices to connect to on the "Bluetooth and other devices Settings" page. In theory, you should be able to connect your Xbox One controller simply by pressing the power button, and then pressing the circular connection button on the top of the controller next to the Micro USB port. All you need to do is make sure that your PC's Bluetooth connection is on - Search for "Bluetooth and other devices Settings" from your Taskbar. This tells your PC to look for your controller. Then on your Windows PC, choose Add Bluetooth or other device and click Bluetooth.
The button is on the front of the controller near the USB port. If you have the latest Xbox One controller designs with Bluetooth functionality and a PC or laptop with Bluetooth functionality, you don't need the Xbox Wireless Adapter to connect the Xbox One controller wirelessly. Press and hold the Connect button on your Xbox controller for a few seconds.