What is a .MSU file?
MSU is the package format for standalone Windows updates.
- Did you know
- MSU files are the patches you install when updating Windows by hand.
- An MSU bundles the update’s payload as a CAB cabinet alongside an XML manifest of metadata, prerequisites and applicability rules.
- The format arrived with Windows Vista and is handled by WUSA, the Windows Update Standalone Installer.
- What Analyser reads
- Open more archives, packages and installers: macOS XAR/.pkg/.mpkg installers (member list), Windows .msu updates (CAB), Snap SquashFS packages, Flatpak bundles, StuffIt (.sit/.sitx), lzop (.lzo) and Brotli (.br) streams, Java Web Start (.jnlp), and the .tlz/.tbz/.tz compressed-tarball shorthands.
- Depth of analysis
- .MSU is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .MSU file
- Drag a .MSU file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.