"The StarCraft II Installer requires an online connection in order to install, and cannot currently connect to the Internet to authenticate. Please check your firewall settings and ensure that your computer is properly connected to the internet, then restart the Installer. If you continue to experience problems, please contact Blizzard Technical Support." This is the error message I got. Someone please walk me through this. I'd appreciate it.
In IE, upper right hand corner, or middle, depending on version, click Tools. Click Internet Options. Click the Connections tab. Click LAN Settings. Please report which boxes are checked, and if any are checked that are not the top box, uncheck them. Only the top one should have a checkmark, unless you are part of the .000001% of the population that requires a script in the middle box. You would know if you needed checkmarks in the bottom two. Try that, post back with results.
Also, bnet is kind of down-ish right now, some people can't sign in, that could be the source of your issue too.
If unchecking that box doesn't work, my FAQ and read about port fowarding on a router. If your at a collage/university campus, then you may out of luck. How are you connecting to the internet? Please let us know.