1. 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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2. 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.

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3. Enable Web Browser automatic configuration within the ISA Firewall Client

1. Open ISA Firewall Client.
2. Click on Automatically detect ISA Server.
3. Click on OK Button.

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4. Enable Automatically detect setting within Internet Explorer.

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 Automatically detect setting.
6. Click on OK button.

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