Open MSU File
An MSU format and extension file is nothing more than a Windows update package and contains source code used to initialize system updates, fixes, and patches for Microsoft Windows systems.
The MSU file is installed by the standalone Windows Update installer (Wusa.exe), which Windows Update runs automatically, which means that the user generally does not need to manually install the MSU files.
The Windows Update applet is an application included with many versions of Microsoft Windows OS, including Microsoft Windows Vista, Microsoft Windows 7, and Microsoft Windows Server.
Earlier versions of the Windows operating system used the MSI format and extension for updates.
How to open MSU files
Typical MSU application file locations:
%systemroot%\system32\wusa.exe "%1" %2 %3 %4"C:\Windows\system32\wusa.exe" "%1" %2 %3 %4 %5 %6 %7 %8 %9
Frequently associated Windows objects:
Microsoft.System.Update.1