1. Remove invalid characters from the proxy exception list and then clear the proxy cache.

1. Open Internet Explorer.
2. On the Tools, select Internet Options.
3. Click on the Connections tab.
4. Click on the LAN Settings.
5. Click on the Advanced button.
6. Please delete any entry in the Exceptions section.

Next, clear your proxy cache.

1. Click on Start, and then click Run.
2. Type cmd in the Open box to get a DOS prompt.
3. Type proxycfg -d at the command prompt, and press Enter.
4. Type net stop wuauserv at the command prompt, and press Enter.
5. Type net start wuauserv at the command prompt, and press Enter.
6. Now try the site again.

Did this resolve your problem?

2. A misconfigured Proxy/Firewall can cause this problem. Double-check the Proxy/Firewall settings. Add the following urls to the exception list within your Firewall/Proxy:
http://*.update.microsoft.com
https://*.update.microsoft.com
http://download.windowsupdate.com
For help configuring Proxy/Firewall refer to documentation or contact the manufacturer.

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3. The corporate environment does not have autoproxy implemented. Automatic Update will always do autoproxy detection and thus if that returns no proxy, it will try to use no proxy. Use the proxycfg tool to specify a proxy server to use (proxycfg.exe -p <proxy server>). Please contact your network administrator to find out the name and port of this proxy.

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4. You are trying to access Windows Update using VPN. The website and Automatic Update may not function properly. Autoproxy is not picking up the wpad.dat proxy configuration file to determine the proxy to be used for the target URL. Thus we are going with no proxy.

1. Try to access Windows Update while not using VPN connection.
2. Use the proxycfg tool to specify a proxy server to use (proxycfg.exe -p &lt;proxy server>). Please contact your network administrator to find out the name and port of this proxy.

Did this resolve your problem?