I have used the Cisco VPN client for years, and on XP it is pretty much rock solid, on Vista, not so much. You might be able to connect, but unless you set up a constant ping to something, it usually will disconnect, with this error:

Reason 442: Failed to enable Virtual Adapater

Now, most sysadmins will say, update you client - yes, I know, it hasnt mitigated the issue, ever. I have been using it on Vista since it came out, and updated my client every time a new update comes out.

I have used it where the VPN server was a Cisco PIX and a Windows Box allowing the Cisco Client to connect.

Anyone have any fixes that you can do on your client to fix this issue?

  • works, sometimes. I tried an NCP client (30 day free trial, $144 after, and it works, no issues, ever) Jul 9, 2009 at 21:05

8 Answers 8


This problem has been fixed in Cisco VPN Client I would recommend using or the new version


Really your best bet is to use the AnyConnect client. It's my understanding that Cisco is moving away from the fat client and it's notoriously buggy on Vista.

  • i am going to try this and if it works good, this will be the solution! May 1, 2009 at 12:22
  • AnyConnect doesnt support ipsec. :( Jul 26, 2009 at 0:23
  • It can work but isn't officially supported.
    – GregD
    Jul 26, 2009 at 5:13

I've run into this issue so often - as Joseph says, it's fixed as of (stupid versioning, Cisco!), and I am currently running with no problems.

On my personal laptop, whenever I ran into that issue, all I would have to do to fix it was disable and re-enable the wireless adapter.

Fn + F2 on my Dell Inspiron (sorry, wanted to use the < kbd > tag!)


There is a comment thread spanning over two years on Bill Evjan's blog where people have been discussing the state of affairs with the Cisco VPN client software. As mentioned in GregD's answer, your most viable option is probably going to be AnyConnect. If that doesn't end up working for you, I recommend reading the comments on Bill's blog for other possible solutions.


I have come across the very same problem when I first installed my Cisco VPN client on my Vista box at home. I followed every step that I found on google search but nothing worked. Then I just restart everything - machine & router. I then uninstalled the client and reinstalled. It worked that time. It's crazy but that was all that I needed to do. ;-)


Random disconnects often happen if some power-saving feature is putting your network adapter to sleep (That explains why it works with constant traffic.) or if your WIFI card is trying to aggressively optimize network performance by hopping between several access points.

You can install the newest version of the deterministic network enhancer (search for citrix dneupdate), because this is what provides the "virtual adapter". Sometimes it even helps to enable UDP encapsulation...

By now I just install the ShrewSoft VPN Client when such problems come up. Although this is not a perfect solution, it is a far more efficient one than finding the cisco error. And users seem happy with it. Seems to connect faster.


Issue is that the client is unable to enable the Cisco VPN Adapter. I have been able to find a work around which is, as soon as you initiate the connection through the VPN client, in Network Connections, enable Cisco VPN Adapter. All within 5 seconds - And you will find that it will connect.

Funny enough this is under Windows XP, and not Vista - However I do not believe the symptoms differ at all across the platforms.


If you hit this question due to the error on Windows 8 and cannot even connect, try the hack here:


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