In computer slang, to slipstream is to integrate files from a hotfix or service pack into the original installation media. Microsoft, as well as many other companies, do this as a way of minimalizing the time needed for products to be configured and updated when first installed.
The term is believed to have been introduced by CoffeeCup Software in 1996. It was coined to release new fixes and additions to software without changing the version number of the original application. Simply put, it is to make a change or fix to replace the existing file without notice of version number modifications. This method decreases the number of changes publicly known and reduces the quantity of numerical versions.
Many slipstreamed versions of operating systems have been released on warez networks, particularly Windows XP Borg and Trogdor editions, which are DVDs that include Windows as well as tens to hundreds of pirated, usually cracked software.