You don't need to 'add' it. You should get a screen on the phone asking you how you want to connect. Is it just to charge, are you wanting to access media, etc. Each device lists it a little differently. Once you choose which, then the phone is connected to the computer. Now, if you choose charge only the computer may not 'see' the device so you can't access files on it, however the other options should give you access to the phone. What you can and can't do while connected is a whole other story.
Now, if you are wanting to make the phone a "HotSpot" for the laptop, that is done differently and connecting via USB won't help.
To connect it and use it like that you need to do the following...
NOTE: I wouldn't do it much, laptops use a...