The final release of the new Firewall Client for ISA Server is now available for download at:
The new version can be installed on computers running Windows 2000, Windows NT 4.0, Windows Server 2003, Windows XP, and Windows Vista. It also includes software updates that improve the security and stability of Firewall Client software.
For more information, please refer to the Knowledge Base article:
929556 How to obtain the version of Firewall Client for ISA Server (December 2006) that includes Windows Vista support