Sun Java Enterprise System 5 Update 1 Upgrade Guide for Microsoft Windows

Upgrade Service Registry Dependencies

It is generally recommended that all Java ES components on a computer system (and in a computing environment) be upgraded to Release 5U1. Release 5U1 Service Registry has hard upgrade dependencies on Application Server and Java DB, so these should be upgraded before upgrading Service Registry. Service Registry also requires that Windows Installer patch (126910–02) is already applied.