Just a thought but I wonder if he may have inadvertantly got a dialler program on his system which could be breaking the connection while trying itself to dial up. Well worth running a full virus check and Spybot S&D check just in case.
The Evil Within 2 review-in-progress
Adobe shows still-in-development tools, including automatically colourising black-and-white photos
iPhone X news: Release date, price, new features & specs
Comment transformer un iPhone en borne Wi-Fi ?