IP Geek help needed

All of a sudden my laptop, which has been coming up and connecting to the home network quite cheerfully, is saying that although the network has an excellent signal strength, it cannot connect because it doesn't have a proper IP address.

Clicking Support/Repair tells me that the IP address can't be renewed. "For assistance, contact the person who manages your network." Who is, unfortunately, me and I'm clueless.

Can anyone help? Can I call anyone? (Comments screened to keep contact info private.)