From Microsoft Support site: Hey everyone, I had the same code 10 problem with Teredo Tunnel  Pseudo-Interface when I connected my laptop with a public library router. Fortunately I found this solution which really worked it out! (My OS is Vista x64 SP2, but I think XP and Win7 can also follow the same solution) Solution:1. Open command prompt with administrator credentials (Find CMD and right-click - Run as Administrator).2. Enter netsh environment. Type "netsh" and ENTER.3. "int teredo" and ENTER4. "set state disabled" and ENTER.5. Open Device Manager and uninstall "Teredo Tunneling Pseudo-Interface".6. Open command prompt with administrator credentials once again.7. netsh + ENTER.8. "int ipv6" + ENTER9. "set teredo client" + ENTER10. Open Device Manager and Scan for new hardware.11. Select "Show hidden devices" from the View menu. You will now see that it is present without errors with any luck. Sources: [URL] [URL]
WHAT CAN YOU DO IF THIS IS MISSING  
Microsoft Teredo Tunneling Adapter 