Device Manager (under Network Adapters) shows MS ISATAP disabled with "Windows cannot load driver...(Code 31)". When I try to update the driver, "Best driver already installed" comes up. The option to rollback driver is greyed out. A previous suggestion was to disable it in Dev Mgr and disable IPv6 in Network Connections. However, when I did this, both IE-7 and Windows Mail got a little flaky with some random errors and slow connections. Re-enabled IPv6 and both IE and Mail appear normal. Even tried removing driver but Windows recreates it on next boot with same error in Dev Mgr. Here is the line from Dev Mgr: isatap.(F36ED1D6-98AB-4569-9DD6-03FB92BCB8C6) Is there a way to restore this driver without a complete OS reinstall or System Restore? Or is it even necessary? (Vista Build 5600 32 bit; Dual boot Vista/XP on separate drives; Home network with two computers).

The installed network adapter driver may not support the Microsoft 6to4 adapter. For more information, refer to this Microsoft article. Please try to get the latest version of your network adapter driver and install it. This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration

Hi, Please refer to AZwldcats's detailed explanation in this thread. Generally, it depends on your NIC drivers that is developed by the NIC manufacture. I have quoted the reply as below: "The 6to4 adapter has to do with the upcoming change to the internet. The internet now uses IPv4 (IP Version 4). That is what is meant with the 4 in 6to4. More info here: http://en.wikipedia.org/wiki/IPv4 Every device on the internet has an IP address. As more and more people/devices get on the internet IP addresses are running short. As of April 2008, predictions of exhaustion date of the unallocated IANA pool seem to converge to between February 2010 and May 2011. IPv4 has 4,294,967,296 possible IP addreses. The next step is IPv6 (IP Version 6) The 6 in 6to4 IPv6 supports more than 300,000,000,000,000,000,000,000,000,000,000,000,000 possible addresses! The 6to4 adapter Allows to use your computer on both networks at the same time..... Currently only a few major corporate networks IPv6. For 99% of the poeple out there your aren't using IPv6. So the 6to4 adapter can be disabled. Most of you are probably getting errors due to your NIC drivers. As IPv6 gets closer manufacturers will release newer drivers that will allow them to be used on IPv6 networks and the 6to4 adapter will then be able be installed correctly.... So as of now, Disable it and don't worry about it! It will not affect your internet experience!!!! " So, please feel free to disable the NIC adapter. Regards, Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.