The wife's Pavilion G7 has given us a bit of grief. She bought her machine at the same time I bought my Asus K55N, and for a while it looked like she got the better laptop. While mine has needed a keyboard replacement, I've had to practically tear hers down to the bare metal to replace the CPU fan. It's had numerous little issues, including a period of time it was giving her the "blue screen of friendship."
So right before I leave town on a road trip, I say to her "hey, you know you can upgrade to Windows 8.1 for free if you go to the Windows store." and she does. And of course, it stops working after the upgrade. It says it's connected to the Internet, but no web sites will come up in a browser. It had to sit on the dining room table waiting for me to get back from my trip. Then I asked her "do you want to go backwards or forwards?" Dumb question, so I sat down to figure this out.
The symptoms were strange. If I tried to ping a site, it would resolve the DNS and show the site's IP address, but the ping wouldn't get a reply. But doing a tracert command would work just fine. If I tried to connect the browser to a plain IP address, that wouldn't work. Turning off the Wi-Fi and connecting it to a wire had the same effect. I uninstalled her virus scanner just for giggles. Those types of apps could certainly stop internet traffic. Same problem.
Eventually I found this link from HP tech support, instructing a user to reset their TCP/IP stack, and it worked! It makes perfect sense because the symptoms I was seeing indicated something wrong with the TCP/IP stack. I've never seen Windows networking just break like that, so resetting the stack is something I've never had to do before.