I am experiencing the same error that I have noticed a number of people are having problems with. I have a system running Windows XP that I installed version 3.51 E of the VPN client on. Everything was working fine, until I made the mistake of running the Network Connection Wizard. After doing that, the Internet Connection Firewall was enabled and I began getting the error message "The necessary VPN sub-system is not available. You will not be able to make a connection to the remote IPSec server." I am able to connect, but no traffic is sent over the VPN. Also, I have general TCP/IP problems connecting to resources on the local network. Uninstalling the VPN client clears these problems up.
I have tried installing the client on another workstation on the same network and it works fine, so I am sure the problem is due to the ICF. I have since disabled it and also tried using system restore to go back to a previous configuration. Unfortunately, I still get the error after installing the VPN client.
I have also tried running the netsh command, following the instructions in Microsoft Technet article Q299357, to reset the TCP/IP configuration to the defaults, but all to no avail.
Any help on this would be greatly appreciated.
Thanks,
Steven A. Fletcher, A+, MCP, MCSE (NT 4), Compaq Master ASE, CCA, CCNA
BCSC
sfletcher@bcsc.com
