the question has been asked multiple times today, this week, for over a year, and even in the last hour. the answer does not change? It does get rather old for some of us who see the same question day and month after month.
It is and has been deplorable and has not been officially addressed or acknowleged. To the best of my knowledge this you can do, besides keep retrying -
Boot Camp 4.0, OS X Lion: Frequently asked question
create a Windows support software (drivers) CD or USB storage media
Boot in Safe Mode and try to download the Windows Support Software and follow these tips:
Advanced Network: Proxy Settings, I uncheck "Auto Proxy detection" and make sure you have the interface you use selected and none others.
"Go into System Preferences - Network - Advanced - Proxies Uncheck "Auto Proxy Discovery", click OK, Apply"
After Unchecking "Auto Proxy Discovery" I also had to Uncheck "Use Passive FTP Mode (PASV)" and then Restart Boot Camp Assistant.
odiggy's comment and tried restarting Boot Camp Assistant. That did the trick, even though the Auto Proxy Discovery checkbox ended up the same as it started. Windows support software is now downloading... if you're downloading to an external drive make sure there's a least 1 GB of free space because the WindowsSupport folder is around 700 MB and presumably will grow with time.
Also, Change Domain Name Servers to OpenDNS IP address servers - that should be at the router firewall rather than the OS but may be in both for some people. You may be using the defaults your ISP uses, save those if you want, and try these:
Make sure you are not using LittleSnitch or Symantec (probably other 3rd party firewall) which do interfere, a Safe Boot should bypass their loading also - there are other products that interfere as well and some now with Mountain Lion.