devcon.exe 64 bit version
11/19/10

Had an issue with Nikki's 64bit Windows 7 laptop not connecting to network shares today, and after some research it turns out that it's because if the Virtual WiFi adapter is on, Windows 7 unexpectedly creates a bunch of Microsoft 6to4 adapters (6to4 adapters are a components used for transmitting ipv6 packets trough ipv4 network correctly) after the computer is rebooted. This over time seems to kill some of the networking functionality of the machine. I looked in Device Manager's Network Adapters section and it listed over 200 of these 6to4 adapters just sitting there! (Make sure to go to View > Show hidden devices in Device manager to see them.) I found a site that talks about removing these adapters using a program Microsoft provides called devcon.exe but that didn't work on Windows 7 64, so I had to download the Windows Drivers Kit image and find something called "setuptools_x64fre.msi" in it which had the 64bit version of devcon.exe.

Download the WDK ISO and extract devcon.exe from it (or just download devcon.zip directly from here and extract it if you don't want to mess around with a 600mb ISO)

How to use devcon.exe to remove all Microsoft 6to4 adapters:

1) Extract devcon.exe to c:\temp from either the ISO or the direct link above.
2) Click Start > All Programs > Accessories, right click on Command Prompt and run as administrator.
3) type cd \temp
4) type devcon remove *6to4MP*

Removing all--possibly hundreds--of the adapters might take a few minutes. After it's done, restart the machine and the network shares should be available once again.

If you don't want these 6to4 adapters to be created over and over again, you might want to check out this solution or request the hotfix from Microsoft.

Update: The hotfix seems to work.

Entry ID: 000454