Solution to Reason 442: Failed to Enable Virtual Adapter with Cisco VPN Client on Vista x86

UPDATED July 2008 : Please see below for updated solution to this problem

Again and again I see people complain about this error message (e.g. CISCO VPN Client Software on Windows Vista)

This is actually a quite easy (but annoying) thing to fix. Here's the 100% reliable method I use to fix this.

1. In Network Connections, right-click your Cisco Systems VPN Adapter which should be disabled and enable it
     
2. Right-click your Cisco Systems VPN Adapter again, this time selecting "Diagnose", and you should get the following prompt (your adapter may be numbered different from Local Area Connection 3)
   
    
3. Select "Reset the network adapter ........ ", this will take a while (around 60 seconds on my laptop)
   
    
4. Windows will again prompt you saying the IP configuration is still invalid, ignore this and just press Cancel. 
5. Go back to the Network Connections, right-click your VPN Virtual Adapter and Disable. 
6. Now open Cisco VPN, and you should be able to connect without any issues.

The problem will reoccur every time the connection is not cleanly closed - i.e. suspend / hibernate / loss of signal. However all you need to do is follow the above steps and it'll reset itself.

Update: This problem has been fixed in Cisco VPN Client 5.0.03.0530. Please speak to your Cisco supplier to obtain this new version. When disconnecting from a VPN connection it appears the new client performs these actions for you automatically (it takes around 60 - 90 seconds now to disconnect from the VPN session). I am unable to redistribute the client from this site - please speak to your Cisco supplier / IT Team.