Wifi only connects to cell phones

What exactly happens when one of the laptops does not connect? Any error message?

If either of the laptops is running Windows ...

Please attach a screen shot of the Networks page (don't collapse the Radar, Connection or Signal History) of the Xirrus Wi-Fi Inspector. If you need help with a screen shot see TSG Posting a Screenshot. FWIW to take screen shots with Windows Vista or latter I prefer to use the built-in Snipping Tool.