Problem: According to Device manager the Microsoft Teredo Tunneling Adaptor is not working. There's a yellow exclamation marl against it. Under Properies, Device status says This device cannot start. (Code 10). Removing and re-installing the device does not solve the problem.
Solution: In Zone Alarm went to "Firewall" (main) and clicked on "Advanced." In "Advanced" under "Network Settings" checked the box for "Enable IPv6 in networking." Closed ZA and reboot.
Issues Found on Machines: Dell OptiPlex Series running Windows 7 64-Bit.