Start with what you already know
If the phone works on the same Wi-Fi at the same location, the router and internet service are probably not completely down. That makes the laptop the best place to start.
Forget and reconnect
Forget the Wi-Fi network on the laptop, reconnect and enter the password again. This can clear a bad saved profile without changing the router for everyone else.
Check adapter and IP details
Verify the wireless adapter is enabled and inspect ipconfig. A self-assigned 169.254.x.x address points toward DHCP or local connectivity trouble.
Check DNS and proxy settings
If the laptop can reach external IP addresses but websites do not open, check DNS. Also verify that an old VPN or manual proxy is not intercepting traffic.
Driver and hardware checks
If networks disappear, connections drop repeatedly or the adapter behaves differently after updates, check the laptop manufacturer's current wireless driver and test close to the router before assuming the router is faulty.