Microsoft Knowledge Base Article 926140 contains the following INTRODUCTION:

This article describes the installation packages for the localized versions of Windows PowerShell 1.0 for Microsoft Windows Server 2003 with Service Pack 1 (SP1) and for Microsoft Windows XP with Service Pack 2 (SP2). These packages automatically install the Release to Web (RTW) versions of Windows PowerShell 1.0. Also, these packages are later versions of the release candidate versions of the product.

There are two installation packages and a Multilingual User Interface Pack (MUI) for Windows PowerShell 1.0. Select the installation package for the language type and for the operating system on the computer.

Localized Install the localized installation package if you are running a version of Windows that is localized for German, Spanish, French, Italian, Japanese, Korean, Portuguese, Russian, Chinese Simplified, or Chinese Traditional.

English Install the English version of Windows PowerShell if you are running an English version of Windows. Alternatively, use this version if you are running a version of Windows that is localized for a language other than German, Spanish, French, Italian, Japanese, Korean, Portuguese, Russian, Chinese Simplified, or Chinese Traditional. For more information about the installation packages for the English versions of Windows PowerShell, click the following article number to view the article in the Microsoft Knowledge Base:

            926139 Windows PowerShell 1.0 English installation package for Windows Server 2003 Service Pack 1 and for Windows XP Service Pack 2

MUI Language Pack Install the English version of Windows PowerShell 1.0, and then install the MUI Language Pack for Windows PowerShell 1.0 if you are running an MUI version of Windows. In MUI versions of Windows, the Windows interface can be displayed in multiple languages. For more information about the MUI Language Pack for Windows PowerShell, click the following article number to view the article in the Microsoft Knowledge Base:

            926141 Windows PowerShell 1.0 Multilingual User Interface Language Pack for Windows Server 2003 with Service Pack 1 and for Windows XP with Service Pack 2

Caution Before you install Windows PowerShell 1.0, uninstall all earlier versions of Windows PowerShell 1.0 from the computer. For support in uninstalling Windows PowerShell, see "Uninstall Windows PowerShell" in this article.