Service pack

In computing, a service pack comprises a collection of updates, fixes, or enhancements to a software program delivered in the form of a single installable package.

Companies often release a service pack when the number of individual patches to a given program reaches a certain (arbitrary) limit, or the software release has shown to be stabilized with a limited number of remaining issues based on users' feedback and bug reports.

Application service packs replace existing files with updated versions that typically fix bugs or close security holes.

Depending on the operating system and deployment methods, it may then be necessary to manually reinstall the service pack after each such change to the software.

This was, for example, necessary for Windows NT service packs; however, from Windows 2000 onwards, Microsoft redirected setup programs to use updated service pack files instead of files from the original installation media in order to prevent manual reinstall.