What are MSP files?

MSP files, or Microsoft Software Patch files, are designed to update applications installed via MSI (Microsoft Installer) files. They contain only the changes between software versions, making updates efficient and less resource-intensive.


  • Efficient Updates: MSP files are smaller in size since they only include the changes, reducing payload and bandwidth usage.
  • Targeted Patching: They simplify the update process by focusing only on specific modifications, minimizing the risk of disrupting other parts of the application.


  • Dependency on MSI: The original MSI file is required for applying the patch, which can be inconvenient if the original file is not readily available.
  • Potential for Issues: Improper management of MSP files can lead to patching problems or software instability, necessitating careful handling.

MSI vs MSP Files:

MSI files are used for the initial installation of software, containing all necessary components. In contrast, MSP files are used for updating existing installations and contain only the changes or patches. To add files to an MSP, you need to create a Minor upgrade for the installer, test it, and then generate the patch from the comparison.

Usage and Removal:

MSP files can be installed similar to MSI files just by invoking them. While creating the MSP files, there are options to make the file ‘uninstallable’ or not. When chosen, the user would be able to uninstall them. Otherwise they are removed only upon uninstallation of the original MSI file.


MSP files are crucial for maintaining and updating software efficiently. Proper management ensures smooth updates and minimal disruption to users. Understanding their pros and cons helps in leveraging their full potential for software maintenance. Proper usage and removal practices ensure that MSP files contribute positively to software management.


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