Go to device manager. Right click on the device and select uninstall. When asked about removing drivers, click yes. Reboot the system. Win 7 will detect the "new device" and re-install the drivers properly. Good luck!
Dear COLGeek thank you so much for the information. I did not have any sound on my media player or videos and ATT told me I had a hardware problem, to call Acer. Well I was determined to keep finding information on Microsoft Teredo Tunneling Adapter because that is what my computer detected as a problem and I came to you link and did what you said and my sound is back and my videos does start and stop any longer. I been trying all afternoon. So thank you for posting them instructions. cookie