Internet Troubles

Have multiple computers and mobile devices on a home network.  On a desktop computer that is plugged in to the router, there are no problems, can reach the internet.  On one laptop connected by Wi-Fi, can't reach the internet.  On another laptop connected by Wi-Fi, can reach the internet.   On an iPad connected by Wi-Fi, can reach the internet but can't send any messages through the iMessage program. 

Not sure what triggered this, out of the blue.  Can you help me get all functionality restored on all devices?

Have you tried power cycling your Modem/Router/wireless Access Point and also the laptop that is having problems?

Regards

paws