I've disabled my anti virus (NOD32), disabled my anti virus firewall. I'd recommend changing this: Proxy settings on your system can also block access.added all the Battle net and blizzard downloader ports (TCP UDP) to my windows firewall, released and renewed my ipconfig, flushed my dns, started secondary logon service, deleted Battle net folder in program data (this is something I have to do every single time btw otherwise it gets stuck on Updating battle.net), I don't use a proxy, I don't use Hamachi. Make sure to disable proxy settings from the control panel: Pull up your Control Panel and select Internet Options. Click the button called "LAN Settings"Uncheck all of the options on that screen. The bolded part wasn't my problem, however like Sealion posted, the "Automatically detect settings" option was the problem... The app still sucks though, I hate the fact I need multiple "stores".We've recently become aware that playing Diablo III with the latest Catalyst 12.4 drivers for ATI cards may cause some visual artifacts for specific hardware configurations.This issue affects users of ATI Radeon HD 2400, 2600, 2900, 3400, 36 graphics cards under Windows Vista and Windows 7.I spent six hours trying to download battlenet but this fixed it in 30 seconds. PS: I don't think resetting the whole pc was neccesary. I pasted it into chrome and my antivirus had it blocked and asked me if I trusted that page.
Update: ATI has released a Catalyst 12.4a driver hotfix for the affected cards. I copied the urls I found in the logs ( I think there is only one).I accepted then deleted the whole file located in Program Data, restarted the installation and it worked. I copied the urls I found in the logs ( I think there is only one).Graev has Windows Vista and could not get past the “Updating Setup Files” little window that came up. ) This one worked for me: try and find the agent application in the folder (for example C:\Documents and Settings\All Users\Application Data\battle.net\Agent). Check the folder you downloaded your files into for any that say . Run the downloader in the same directly you chose originally and it should fix the files automatically and/or finish downloading. We scoured the support forums for days, Googled, and had no luck until tonight. Choose Windows XP (Service Pack 3) (Note: Does not work on Vista.) Right Click the Icon, Run as Administrator. Delete your C:\Program Data\Blizzard Entertainment\Cache folder. Run the Downloader again, as administrator, and see if it gets past the “Updating Setup Files” window. Start the agent application manually and after that start Diablo III setup file in your Diablo-III-8370-en GB-Installer folder. Fix #4a – Clarification for Fix 4 by Garythe Oak 1.