Showing tag results for Architecture

Jun 16, 2026
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Third Rule of MSIX

Howard Kapustein

MSIX has several core principles underlying its design and implementation. Engineers half-jokingly call these The Rules of MSIX. The Third Rule of MSIX is arguably the most important and certainly the most foundational: Package identity is unique across space and time Packageidentity is a unique identifier corresponding to a specific set of b...

Jun 9, 2026
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Staging Part 2 – Disk Space Optimization

Howard Kapustein

"Disk space optimizations" is one of the key features of MSIX: Disk space optimizations. With MSIX there is no duplication of files across apps and Windows manages the shared files across apps. The apps are still independent of each other so updates will not impact other apps that share the file. But how does MSIX accomplish this? Every pac...

Jun 2, 2026
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Staging Part 1 – Sharing is Caring

Howard Kapustein

A key phase in installing a package is staging the package: When a package is staged for the first time, deployment performs several actions, including: Deployment secures these directories with strict permissions, typically granting users Read and potentially Execute access - but notably not Write access. This ensures one user cannot ...

May 27, 2026
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Deployment Operations, Requests and Queue

Howard Kapustein

The PackageManager API submits requests to the deployment engine for processing. Each request represents an instruction for the deployment system to carry out a defined set of actions, collectively referred to as a deployment operation. The operation associated with a request depends primarily on the API used to initiate it and, in some cases, its...

May 19, 2026
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Package Identity

Howard Kapustein

An MSIX package identity is composed of a five-part tuple that uniquely identifies a package. It consists of the following attributes: Together, these fields form the canonical identity of a package. Programmatically, this identity can be represented using APIs such as Windows.ApplicationModel.PackageId or the PACKAGE_ID structure. Why Pa...

May 4, 2026
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There is no Install – it’s ‘Stage’ and ‘Register’

Howard Kapustein

"Is ContosoParts.msix installed?" is a common - but misleading - question The term install is not a formal concept in MSIX. This may seem paradoxical for a deployment technology, but it makes perfect sense once you understand MSIX deployment’s core architecture. Deployment Requests A caller makes a deployment request to the deployment engine vi...