What is the Cisco VPN Client error message "Required VPN subsystem not available"

When starting up the VPN client software, I get the following error message: “Required VPN subsystem not available”. Why?

There are several possible reasons why this happened; most likely tied to the Cisco VPN Service. A lot of times I’ve seen this happen because the VPN service starts up before any working networking connection has started. Try the following steps:

1. Restart the Service
a) Make sure you have a working network connection. If you are using the wireless UCLAWLAN, see if you can reach any UCLA website like http://www.bol.ucla.edu. If you are using a wired connection, see if you can reach any website like http://www.google.com
b) Restart the Cisco VPN Service. Click Start → Run… → type in “services.msc” → Right-Click on “Cisco Systems, Inc. VPN Service” → select “Restart”

2. Reboot the Machine

3. Un-install and re-install the VPN service

Marked for deletion on 11.15.2022 by Chang, Henry
Reason: Old Cisco VPN Client that pre-dates Cisco Anyconnect/Secure Client. This was retired back around Windows XP/Vista.