Based on my research, the Microsoft 6to4 Adapter actually is a virtual device which does some conversions between IPv6 and IPv4. Please also refer to the following Knowledge Base:
http://support.microsoft.com/kb/932520
This may be not affect the network connections. Regarding the issue that the computer cannot connect to the wireless network, please try the following suggestions:
1. Please completely remove the driver of the wireless NIC from both Device Manager and “Control Panel – Programs and Features”, reboot the computer and reinstall the driver again. If there is a new version of driver released, please also try it. (If you want, please let me know the exact brand and model of the Wireless NIC, and we may help you check the manufacturer’s website.)
2. Check the network settings:
Please go to “Control Panel – Network Connections”, right click on your connection and choose “Properties”. (if you have multiple connections, please check the one you use and disable the unnecessary ones. )
1) On the “Network Tab” of your Connection properties, please choose “Internet Protocol Version 4” and click “Properties”. And then check if both of the IP Address and DNS are set to be delivered automatically.
2) If it is set to obtain the IP Address and DNS automatically, please try to manually assign IP address, subnet mask, default gateway and the DNS settings referring to your router’s settings to see if this works.
3. Based on my experience, the issue may also be related to the firmware of the router. Therefore, I would like to suggest that you also check your wireless router manufacturer’s website and check if there is any upgrade version of firmware.
If everything worked before, a quick solution is to restore the system back to the previous status when the issue didn’t occur with System Restore. (Note: Performing a system restore may cause the loss of the current system settings; therefore, before doing this, please make sure that the system restore point is not too old and set a restore point for the current status.)
If the issue persists, please run “CMD” and then “ipconfig /all” to export all the network settings and post the information to this thread.
6to4 adapter is a component used for transmitting IPv6 packets trough IPv4 network correctly.
In some scenarios, there will be a code 31 or code 10 error appearing beside this component. A possible reason is, the network adapter doesn’t support this feature. You may update the driver for your network adapter or chipset, and then try to uninstall and reinstall the this component.
To uninstall the component, right-click the item in Device Manager and select Uninstall.
To reinstall the component, in Device Manager, Action – Add Legacy Hardware – Next – “Install the hardware that I manually select from a list” – Network adapters – Microsoft – Microsoft 6to4 Adapter – Next – Finish the wizard.
If the steps above doesn’t solve the problem, your network adapter is not a supportive one for this component. You can completely ignore this error, if there isn’t IPv6 network deployed in the environment. The error won’t affect your system.
To remove the error message, please right-click the Command Prompt and run as administrator, type the command netsh in 6to4 set state disable, press Enter. The component will be disabled and hidden
Hope this helps. Thanks
http://social.technet.microsoft.com/Forums/en-US/itprovistanetworking/thread/3cd28c95-3344-4908-9631-f441f6568119