From my experience with windows, this means exactly what it says. Try using Arduino Builder with no internet on your computer (disable WiFi and unplug the ethernet). You can try clicking the "refresh page" link. Lastly, you should try re-downloading Arduino Builder and putting it somewhere else on your machine. Is your computer fully updated (Windows Update)? Are you using the most recent version of Internet Explorer? Is your antivirus/firewall blocking the connection? Speaking of which: what is your antivirus program? Is there anything in its log saying it blocked Arduino Builder? Have you restarted your computer?
What this definitely means is that Arduino Builder somehow relies on the internet to run. Personally, I think that is a major problem in the application. Try everything above.