If your computer has a Bluetooth adapter, simply go to Settings > Devices > Bluetooth & other devices, then Add Bluetooth or other device.
If your computer does not have Bluetooth, you can buy an adapter relatively inexpensively on sites such as Amazon. If you have a free PCIe slot, get a PCIe Bluetooth card, otherwise, you'll have to get a USB dongle. Once you install this, just follow the steps above to pair your earphones (while your earphones are in pairing mode of course).