这是一个已知问题：  http://annabooks.com/Articles/Articles_WES7/Disk-and-Ram-Resource-Issue-with-Windows-Embedded-Updates-Rev-1.2.pdf

如果要从WEDU安装更新，则必须使用备用解决方案。例如，安装带有一些更新的图像，然后使用配置集添加其余图像。

You will have to use an alternate solution if you want to install updates from WEDU. Foe example, install an image with a few updates, and add the rest using a configuration set.