To configure the firewall for software updates
Configure the firewall to allow communication over HTTP and HTTPS ports (80 and 443).
Make sure you're allowing all of the Windows Update URLs. Here is a list of URLs you'll also want to make sure are allowed:
URLs:
http://windowsupdate.microsoft.com
http://*.windowsupdate.microsoft.com
https://*.windowsupdate.microsoft.com
http://*.update.microsoft.com
https://*.update.microsoft.com
http://*.windowsupdate.com
http://download.windowsupdate.com
http://download.microsoft.com
http://*.download.windowsupdate.com
http://test.stats.update.microsoft.com
http://ntservicepack.microsoft.com