You can't get to the North America based Discovery Service url(disco.crm.dynamics.com/XRMServices/2011/Discovery.svc). Check ...

You can't get to the North America based Discovery Service url(disco.crm.dynamics.com/XRMServices/2011/Discovery.svc). Check to make sure that TCP Port 443 is open on your firewall.  Click on the link 'Help me fix this issue' in the actions pane located on the right side of the screen for assistance.