Migrating from ISA 2004 EE to 2006 EE is an easy process. Upgrade Guide for ISA Server 2006 Enterprise Edition
However, you may run into some technical errors:
“The ISA Server configuration cannot be imported because it was exported from a computer running an earlier version of ISA Server without requesting inclusion of the user permission settings or confidential information. For upgrading, the configuration must be exported with inclusion of these settings and the confidential information.”
This error was encounted when upgrading an array member to new equipment instead of performing an in-place upgrade.
To work around this problem, follow these steps.
Before Exporting ISA Server 2004 Configuration Storage server you need to make sure that the account you are using has “ISA Server Enterprise Administrator” role. This role allows full control over the enterprise and the configuration of all arrays in the enterprise. Users with this role can Import (Restore) Configuration and follow the on-screen instructions without running into the above error.
For more in-depth practical guide for upgrading ISA 2004 EE arrays to ISA 2006 EE. Please feel free to contact me for further technical assist, with the installation of your ISA Solutions.