Before we get into some of the good things that the new ADMX files do for us, I should point out that Windows server 2008 and Vista can continue to use the old ADM files. For example, if your organization has created some ADM templates with custom Registry settings, you can still import them into your GPOs as always, using the Administrative Templates node in the Group Policy Object Editor (GPOE). However, you may want to consider converting your ADM templates into the newer format, to take advantage of central store management, dynamic loading/unloading, and multilanguage support.

Originally, Microsoft had said that they didn't intend to provide an ADM-to-ADMX migration tool, but enough people howled and hollered that they changed their mind, and ADMXMigrator.MSI is the result. The tool is only available to those whose Windows installations are validated as part of the "genuine Microsoft Windows" program. It can handle converting multiple ADM files at one time. Just be aware that you will lose any comments in your ADM files when you convert them.

A nice side benefit to this download is the inclusion of an ADMX file editor that makes the process of tweaking ADMX files significantly easier.