Vista : duplicate name exists on the network

[DAR2133576]

In case people are still having issues with this (as I was)  I found the answer here: http://forums.techarena.in/windows-server-help/1141789.htm

This is an excerpt from the post:
-------------------------------------------------
Start with an elevated command prompt

The following procedure will show no-longer-connected devices in Device
Manager for Server 2008.

1) Open a command window with elevated privileges (Start -> Right-click
"Command Prompt", select "Run as Administrator")

2) In the command window, execute the following commands:

SET DEVMGR_SHOW_NONPRESENT_DEVICES=1

START DEVMGMT.MSC

The second command starts the Device Manager. It MUST be started from the
elevated-privilege command window for this procedure to work.

3) In Device Manager, click the VIEW menu item and select "Show hidden
devices".

This should show any hidden devices. For network adapters, expand the
network adapters node. Right-Click any device you wish to remove, and click
Uninstall.

Ah thanks a lot for providing an answer to this so I didn't have to struggle anymore on trying to get it working. Really appreciate it!

[retes23]

I've been experiencing the same problem. I tried everything you guys have suggested but none of them worked. I do hope someone can help us.

[ravenstar]

Hi retes23

First off to shorten additional commands I usually start by entering netsh pressing return and then entering int ipv6 and return.  The command prompt will change to netsh interface ipv6>

Once you have done this type show interfaces, this will give you a list of all the currently active IPv6 interfaces.  Check to see if IP6Tunnel is already listed.
If it is then the next step is to delete the interface. - type delete interface IP6Tunnel
Finally to clear up any extra routes etc type reset and then when this has completed reboot the PC.

I'm pretty new to this IPv6 myself but have used the above a few times.  Admittedly I am using Windows 7 but the same steps should apply to Vista.