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 tracking such as Bugzilla. In large software applications such as office suites, operating systems, database software, or network management, it is not uncommon to have a service pack issued within the first year or two of a product's release. Installing a service pack is easier and less error-prone than installing many individual patches, even more so when updating multiple computers over a network, where service packs are common.
Service packs are usually numbered, and thus shortly referred to as SP1, SP2, SP3 etc. They may also bring, besides bug fixes, entirely new features, as is the case of SP2 of Windows XP (e.g. Windows Security Center), or SP3 and SP4 of the heavily database dependent Trainz 2009:World Builder edition.
Incremental and cumulative SPs
Service Packs for Microsoft Windows were cumulative through Windows XP. This means that the problems that are fixed in a service pack are also fixed in later service packs. For example, Windows XP SP3 contains all the fixes that are included in Windows XP Service Pack 2 (SP2). Windows Vista SP2 was not cumulative, however, but incremental, requiring that SP1 be installed first.
Impact on installation of additional software components
Application service packs replace existing files with updated versions that typically fix bugs or close security holes. If, at a later time, additional components are added to the software using the original media, there is a risk of accidentally mixing older and updated components. 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 original installation media in order to prevent manual reinstalls.
Decline of service packs
Service packs for versions of Microsoft Windows have been declining.
- Windows NT 3.1 has 3 service packs: SP1, SP2, and SP3.
- Windows NT 3.5 has 3 service packs: SP1, SP2, and SP3.
- Windows NT 3.51 has 5 service packs: SP1, SP2, SP3, SP4, and SP5.
- Windows NT 4.0 has 6 service packs: SP1, SP2, SP3, SP4, SP5, and SP6; and one Option Pack
- Windows 2000 has 4 service packs: SP1, SP2, SP3, and SP4.
- Windows XP has 3 service packs: SP1, SP2, and SP3.
- Windows Vista has 2 service packs: SP1 and SP2; and one Platform Update.
- Windows 7 has 1 service pack: SP1; and one Platform Update. There is also a Convenience Rollup which, though not officially a SP, offers many of the same advantages as one.
- Windows 8, Windows 8.1, and Windows 10 have OS-sized updates that replaced service packs. Windows 10's updates includes visible changes to features in the operating system and are actively marketed by Microsoft.
- Adaptation Kit Update
- Apple Software Update
- IBM Program temporary fix
- Point release
- Slipstream (computing)
- Software release life cycle
- Windows Update
- One counterexample is Microsoft SQL Server 2000 Service Pack 3a
- Example of Service Pack list of changes for a multi-module/multi-mode software product: Trainz SP2 involved feature changes and bug fixes
- Trainz Railway Simulators Service Packs Table versus major release version titles
- Knowledgebase, Microsoft. "List of fixes included in Windows XP SP3". Microsoft. Retrieved 22 November 2012.
- Knowledgebase, Microsoft. "Frequently Asked Questions: Windows Server 2008 Service Pack 2 and Windows Vista Service Pack 2". Microsoft. Retrieved 3 March 2014.
- Not Necessary to Reinstall Windows 2000 Service Packs After System State Changes
- Microsoft Support Lifecycle (includes Microsoft's service pack policy)
- Microsoft Service Packs
- Windows Service Packs
- List of fixes that are included in Windows XP Service Pack 3