I recently got a new laptop (well new to me) at work and was out of the office and needed to tether. I wanted to save my iPhone battery so at first I plugged the iPhone into the laptop via USB and turned on tethering, but the iPhone network device never appeared on the laptop and it wasn't able to access data. After futzing around for a few minutes I decided to just tether via personal hotpot, but the failure over USB was puzzling. I've done it before on my older PC in my office without a problem. Just plug it in and it connects.