Technical Expertise Needed?

I work in tech support and I am really stuck on this one. I was trying to get a guest connected to the internet. She was connected one day and then the next day she was unable to bring up a webpage. At first it said page can't be displayed, then she was able to bring up google but could not browse anywhere else. Her status is greyed out, she is unable to ping, she has changed the modem and all light are on, she also changed the cable and the status is still showing grey. I went into the Nomadix and it came right up and there are other guests connected and using the network. She is DHCP enabled and she is not using a proxy server or automatic configuration script. She was able to display google when I had her turn off automatically detect settings. Now she's getting a pop up that says she's working offline and to click connect but when she does that, it says there is no connection to the internet. I would really like to know what's going on for future reference. Thanks.