Clyde and his wife both have iPhone 5Cs on AT&T, but they get each other's text messages, and their daughter gets them too. Leo says they share text messages because they all are using the same Apple ID. They'll need to create a separate account for each of them. They won't lose their ability to share apps either, because Apple has Family Sharing.
Clyde is also getting a Blue Screen of Death with a DPC error. Leo says that's usually referring to a problem with the SSD Device driver. It's also due to an old operating system, so upgrading to Windows 10 should fix it.