Windows PowerShell 1.0 English update package for Windows Server 2003 Service Pack 1 and for Windows XP Service Pack 2.

Microsoft Knowledge Base Article 925228 contains the following introduction:

This article describes the Microsoft Windows PowerShell 1.0 English update package for Microsoft Windows Server 2003 Service Pack 1 (SP1) and for Microsoft Windows XP Service Pack 2 (SP2). The Windows PowerShell 1.0 English update package will be released by the end of calendar year 2006.