Some of the following I found on these websites, I've ordered it in the way that I think that may apply best to your situation:
http://v4.windowsupdate.microsoft.com/troubleshoot/
http://www3.telus.net/dandemar/updtcl.htm
http://support.microsoft.com/?kbid=193385
Verify the following services are running. Set them to "automatic" and start them if they aren't:
-Automatic Updates
-Background Intelligent Transfer Service
-Cryptographic Services
-Remote Procedure Call (RPC)
-System Restore Service
One way to do this is to go to: Start -> Run -> type “services.msc”
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Internet Explorer:
Add the following URLs to your Internet Trusted sites list in Internet Explorer:
*.windowsupdate.microsoft.com
*.windowsupdate.com
*.microsoft.com
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Verify Internet Explorer connection settings
-Open Internet Explorer
-Go to Internet Options (in older IE versions, Tools -> Internet
Options)
-Click "Connections."
-Click "LAN Settings."
-Delete anything in the Automatic Configure text box and clear the "Use automatic configuration script" check box.
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Set Advanced Internet Explorer options:
-Open Internet Explorer
-Go to Internet Options (in older IE versions, Tools -> Internet
Options)
-Click on “Advanced” tab
-Check the "Use HTTP 1.1" check box.
-Check the "Use HTTP 1.1 through proxy connections" check box.
-Uncheck “Check for server certificate revocation”
-Restart Internet Explorer
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Check your Internet Explorer security settings
- In Internet Explorer click "Tools," and then click "Internet Options."
- Click "Security."
If using "Custom Level."
- Make sure that "File Download" is enabled.
- Make sure that "Run Active X controls and plug-ins" is enabled.
- Make sure that "Active Scripting" is enabled.
- Set your …