Keeping track of when and where your 1603 error occurs is a critical piece of information in troubleshooting the problem.
Below is a list of troubleshooting steps to resolve your Error 1603 problems.
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".
Which has nothing to do with proxies, which threw me off. Having issues with the battelnet app it will not log me in now it was fine this morning and then now it wont upload.
The remaining drivers I seem to be missing are those for printers.
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.i uninstalled it turned all my protections off and firewall run as administrater nothing works!!!!i can log in online in a browser but it wont let me log into war of War of warcraft!I do not presently have any deferred updates and I'm otherwise up-to-date.I had to go into the Device Manager and choose Update Driver on a couple of drivers to have my system download the latest versions from the Windows Update server.