Recently I have had several computers running Windows 7 pro 32-bit having trouble connecting to the network. I support a number of computers on an internal network. The Microsoft ISATAP adapter seems to be at the root of the problem. When I run ipconfig /all, I find these details: Tunnel adapter isatap.(our domain): Media State . . . . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : (our domain) Description . . . . . . . . . . . . . . .: Microsoft ISATAP Adapter Physical Address . . . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled . . . . . . . . . . . . : No Autoconfiguration enabled . . . . : Yes It seems that the adapter in our situation is trying to connect to an ISATAP server, but it doesn't exist and cannot connect to the server or the internet. This was originally affecting two Dell Optiplex 980s, but began to affect some laptops which were not able to connect to wireless, which suggests that this is an OS issue. I found that going into Device manager > View> Show Hidden Devices > Network Adapter and uninstalling the ISATAP drivers will get rid of the problem 9at least so far). I am looking for more information about the Microsoft ISATAP adapter. What does it do? Why does it kick in at random times? Why are these widely problematic ISATAP drivers included in Windows 7? Is there a fix (better than the one I have been using) that we can include on our machine images so we do not have users reporting no internet connectivity?

Hi, The Microsoft ISATAP device Inter Site Automatic Tunneling Address Protocol is used to help enterprises transition to an IPv6 infrastructure. The ISATAP adapter encapsulates IPv6 packets by using an IPv4 header. This functionality enables the client to transport IPv6 traffic over an IPv4 infrastructure. This approach lets organizations slowly migrate to an IPv6 infrastructure without having to spend excessive time and financial resources to convert to the new infrastructure. More detail you can refer: http://support.microsoft.com/kb/932520 As you said “This was originally affecting two Dell Optiplex 980s, but began to affect some laptops which were not able to connect to wireless”. What the error message when you want to connect to wireless? Try to update your wireless driver, also you can try to disable firewall, reinstall Microsoft ISATAP adapter, disable IPv6 for test. Hope that helps. Regards, Leo Huang 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.

We did not receive an error message aside from the yellow exclamation point on the network access icon in the system tray. As I said, I was able to solve the problem at least temporarily by uninstalling the ISATAP drivers. I also found some advice that using the command "netsh int isa set state disabled" (linked below) in the command line should disable ISATAP. Just today the ISATAP adapter drivers were reinstalled somehow on one Dell Optiplex 980, and it lost connectivity. https://techontip.wordpress.com/2010/03/11/fine-tune-windows-2008-r2-networking-config/ According to the ISATAP guide for Windows Server 2008 R2 (linked below), ISATAP is not for use on intranets/production networks (pp. 2). So, our only option is to disable it/ uninstall it completely because as you can see above and as is mentioned in the guide below (page 5), ISATAP looks for a router or a link-local ISATAP address of which we have neither. http://www.microsoft.com/downloads/details.aspx?FamilyID=0f3a8868-e337-43d1-b271-b8c8702344cd&displaylang=en My question is: why is ISATAP automatically enabled in Windows 7 if it seems to cause problems on an intranet? We did not enabled it in our setup. Our network drivers are the most up-to-date. Disabling IPv6 on one machine has kept it free of problems for a couple of weeks. That may be the solution. Has anyone on an intranet had a similar issue rolling out Windows 7? Thanks much, djp