你可以透過 DISM 指令看出目前的WES7系統上已經有哪些 package 在裡面了(Windows 7 FES也可以唷)
You can use the below command to see what are the packages included in your WES7 / Windows 7 image
DISM.exe /online /get-packages
進入正題,當你 download 某些 hotfix / QFE 時,會發現部分的檔案格式是 xxx.msu