>>>>>>I have been using Cisco VPN Client version 5.0.07.0440 for a long time, connecting to many customers.
>>>>>>
>>>>>>Since yesterday, I am not able to. When I click on Connect I get message
>>>>>>
>>>>>>

>>>>>>Secure VPN Connection terminated by Peer
>>>>>>Reason 427: Unknown error occurred at Peer
>>>>>>

>>>>>>The number 427 may change to another number if I try to connect to another customer.
>>>>>>
>>>>>>What would you suggest to try to resolve?
>>>>>
>>>>>If it's happening with multiple VPN customers then the problem is at your end, not any VPN concentrator.
>>>>>
>>>>>Can you try again with your antivirus disabled, especially any network filtering/firewall function?
>>>>
>>>>Yes, this is the first thing I tried yesterday, to shut down Avast (my AV) but it didn't make a difference. And indeed it is my problem because I have another computer with the same version of Cisco VPN and yesterday the other computer worked. And bothe computers are on the same Wi-Fi. I may have to uninstall the Cisco VPN on my PC and install it again; just to see if it will make a difference.
>>>
>>>Just for reference, Shrew Soft has a free Cisco-compatible VPN client at https://www.shrew.net/download/vpn . Note that for Windows 10 you need to make a registry change before installing this product. I've used it fairly extensively and it works well; it can take a bit of time to configure, though.
>>
>>What about Windows 7? Can I use this product? And will existing VPN config files work in Shrew Soft?
>>Thank you.
>
>Yes, it works with Windows 7, 8.1 and 10 - but there is the one registry change you need to do before installing on Win10.
>
>I very much doubt the config files will work directly with Shrew Soft. But if you can read the Cisco config file parameters (i.e. open it and view the fields) you might be able to use them to fill in the Shrew fields. There could well be terminology differences, though - the two products using different names for the same thing. Shrew Soft has some documentation on configuring for various VPNs at https://www.shrew.net/support/Main_Page .

Thank you. I have not yet uninstalled and installed the Cisco VPN (been super busy refactoring a project). But once I reinstall it and if it still does not work, I will try the Shrew Soft.