Cisco VPN Error 56

[Borzoi]

I have spent weeks looking for a solution online but I have turned up with nothing.

I am running Windows XP Professional (this has been tried on both service pack 2 and service pack 3) but every time I try to run the Cisco VPN client I get "Error 56: The Cisco Systems, Inc. VPN Service has not been started. Please start this service and try again"

The obvious solution: Start the service. I do this from services but the service will not stay active. I sometimes get a message saying that it started then stopped and that some services will stop when not used but other times it simply stops. Either way, it will not stay on.

Searching online, the only solution I could find was to disable the service for Internet Connection Sharing. I have disabled "Windows Firewall/Internet Connection Sharing (ICS)" in services and set the start up to Manual so that it doesn't start on boot.

Here is a list of everything I have tried and the results:

1. Manually starting the service - Service stops instantly
2. Disabling Internet Connection Sharing and starting the VPN service - same result as 1.
3. Enabling the network created by the VPN software - is constantly "Obtaining IP address" and doesn't start the service. Starting the service at this point yeilds the same results as 1. and also disables the VPN network connection.
4. To esure it was installed properly, the VPN client was uninstalled and all records of it removed from the registry.
5. Firewall and anti-virus has been completely disabled.

I'm at a loss here. Does anyone have any suggestions for what to try? Have I missed something obvious?

[CimmerianX]

Off the top of my head....

Is this the IPSEC client or the AnyConnect client?
Do you have any other VPN clients on that PC? Many times, multiple ipsec clients don't play nice together.
Don't enable the network on the VPN software, that will happen when you establish a tunnel.....
Did you check your event viewer for any items that occur at the time you start the service?

[Borzoi]

It's the Cisco VPN client 5.0.01.0600.
This is the only VPN client on the computer.
Most of my tests have me leaving the network the VPN created disabled as I know that it automatically gets enabled when the VPN connects.
The event viewer has no errors, just that the service started and stopped:

I've removed my computer name from the below snippets.

Start Event:

Event Type: Information
Event Source:   Service Control Manager
Event Category: None
Event ID:   7036
Date:       14/05/2012
Time:       20:45:40
User:       N/A
Computer:   
Description:
The Cisco Systems, Inc. VPN Service service entered the running state.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Stop event:

Event Type: Information
Event Source:   Service Control Manager
Event Category: None
Event ID:   7036
Date:       14/05/2012
Time:       20:45:40
User:       N/A
Computer:   
Description:
The Cisco Systems, Inc. VPN Service service entered the stopped state.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

As you can see, the service is stopping before even a second goes by.

[Borzoi]

I'm guessing nobody knows what could be happening?

This has stumped everybody I know.