XPS Documents Viewer
Microsoft Connect 4.12曾经放出了一篇 《Windows Vista Product Guide - Beta 2》 文档，使用FTM下载下来以后，还要安装阅读器。阅读这种.xps格式的文档有两种办法：
方法一：是安装WinFX Runtime Components，安装好以后使用IE浏览器就可以打开了。但这个组件是需要从网络安装的，安装客户端需要从网络上下载20MB的文件，当安装程序所处客户端在ISA后面时，会无法连接到远端服务器，似乎是安装程序需要走特定的端口，我看不到服务器端的log，不知道什么端口被公司的ISA block掉了。:(
方法二：XML Paper Specification Essentials Pack (Beta 1)，不需要从网络下载，非常方便。推荐！:)
Opening XPS Documents with WinFX Runtime Components
You can view XPS Documents on your computer that is running Windows XP or Windows Server 2003 with Internet Explorer version 6.0 or later by installing the WinFX Runtime Components. Once installed, XPS Documents with a .xps file extension will open in Internet Explorer using the XPS viewer that is included with the WinFX Runtime Components. From there, you can access advanced XPS Document features such as digital signatures and Windows Rights Management Server support.
The February Community Technology Preview (CTP) build of the WinFX Runtime Components is now available for download and installation.
Download the February Community Technology Preview (CTP).
Opening XPS Documents with XML Paper Specification Essentials Pack (Beta 1)
The new XML Paper Specification Essentials Pack (Essentials Pack) includes a lightweight, standalone viewer that allows you to view XPS Documents on Windows XP, Windows Server 2003, or Windows 2000 (Service Pack 4) without the need to install the WinFX Runtime Components. Once the Essentials Pack is installed, XPS Documents will open in a standalone viewer.
The XPS Essentials Pack (Beta 1) is not fully compliant with the XML Paper Specification; however the final version of the Essentials Pack will fully support the specification. View the exceptions.
Download the XML Paper Specification Essentials Pack (Beta 1)
Viewing XPS Documents created with the Microsoft Office System Beta
Both viewers support viewing XPS Documents created by 2007 Microsoft Office system applications; however, in some cases, the .container file extension created by Office must be changed to .xps for the viewer to recognize the document.
For info about XPS (XML Paper Specification),see
http://www.microsoft.com/whdc/xps/default.mspx