How to obtain the version of Firewall Client for ISA Server (December 2006) that includes Windows Vista support
This KB article will take you to the page that lists the new features of the client as well as a link on where to download it. According to this KB the correct version is 1.0.
The following features are new in this version of Firewall Client for ISA Server:
• Support for client computers that are running Windows Vista
• Software updates that improve the security and stability of Firewall Client for ISA Server