A service pack is a collection of updates, fixes or enhancements to a software program

Computer program

A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

 delivered in the form of a single installable package. Many companies, such as Microsoft

Microsoft

Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

 or Autodesk

Autodesk

Autodesk, Inc. is an American multinational corporation that focuses on 3D design software for use in the architecture, engineering, construction, manufacturing, media and entertainment industries. The company was founded in 1982 by John Walker, a coauthor of the first versions of the company's...

, typically release a service pack when the number of individual patches

Patch (computing)

A patch is a piece of software designed to fix problems with, or update a computer program or its supporting data. This includes fixing security vulnerabilities and other bugs, and improving the usability or performance...

 to a given program reaches a certain (arbitrary) limit. Installing a service pack is easier and less error-prone than installing a high number of patches individually, even more so when updating multiple computers over a network.

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

Windows XP

Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...

.

Incremental and cumulative SPs

A service pack can be incremental, which means it only contains the updates that were not present in the previous service packs or, it can be cumulative, which means it includes the contents of all its predecessors. In the case of Microsoft's products, an incremental update was called a service release. For example, Office 2000

Microsoft Office

Microsoft Office is a non-free commercial office suite of inter-related desktop applications, servers and services for the Microsoft Windows and Mac OS X operating systems, introduced by Microsoft in August 1, 1989. Initially a marketing term for a bundled set of applications, the first version of...

 must be upgraded to service release 1 (SR-1) before one can install SP2.

Recent service packs for Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 have not been cumulative starting with Windows XP Service Pack 3. Windows XP SP3 requires at least SP1 to be present (although SP2 is recommended) on an installed copy of Windows XP, although slipstreaming

Slipstream (computing)

In computer jargon, to slipstream updates, patches or service packs means to integrate them into the installation files of their original software, so that the resulting files will allow a direct installation of the updated software....

 SP3 into the gold release is still supported. An unsupported workaround to install SP3 on Windows XP RTM also exists. Windows Vista Service Pack 2 also is not cumulative and requires at least SP1 to be present on an installed copy of Windows Vista

Windows Vista

Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...

.

Office XP, 2003 and 2007 service packs have been cumulative.

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, but from Windows 2000 onwards, Microsoft implemented a deployment strategy to prevent this (setup programs are redirected to use updated service pack files, instead of files from original installation media, where necessary).

See also

• IBM Program temporary fix
• Adaptation Kit Update
• Hotfix
  Hotfix
  A hotfix was originally the term applied to software patches that were applied to live i.e. still running systems. Similar use of the terms can be seen in hot swappable disk drives...
  
  
• Slipstream (computing)
  Slipstream (computing)
  In computer jargon, to slipstream updates, patches or service packs means to integrate them into the installation files of their original software, so that the resulting files will allow a direct installation of the updated software....
  
  
• Apple Software Update
• Windows Update
  Windows Update
  Windows Update is a service provided by Microsoft that provides updates for the Microsoft Windows operating system and its installed components, including Internet Explorer...
  
  
• Software release life cycle

External links

• Microsoft Support Lifecycle (includes Microsoft's service pack policy)
• Microsoft Service Packs
• Windows Service Packs