My Vista SP1 Laptop refused to connect to our MS ISA VPN for work at some point. There was no error given on the connection interface, but the Application Event Log recorded an Event ID 20227 – RASClient
The user somewhere\someone dialed a connection named WorkVPN which has failed. The error code returned on failure is 800.
Some searching showed others with similar results. The common cause is Windows OneCare. It’s interaction with the Windows Firewall blocks VPN protocols by default. I’m not sure why it doesn’t prompt to allow the traffic, a problem with the application.
The fix is to enable VPN protocols under “Live OneCare Settings” – “Advanced Settings” Button – “Ports and Protocols” Tab – Tick “Virtual Private Network”.
Just in case you’re wondering, it is worth posting this stuff – this saved my bacon, thank you!