for Office XP that would allow up to 500,000 corporate customers to evaluate a Corporate Preview Beta version of the product on a total of 10 machines per copy; individual copies cost $19.95 and expired on August 31, 2001. Office XP was released to manufacturing on March 5, 2001, and was later made available to retail on May 31, 2001. Service packs Microsoft released three service packs for Office XP throughout the product's lifecycle that introduced security enhancements, stability improvements, and software bug fixes; each service pack was made available as separate Client and Full File update versions: Client updates were for Office XP CD-ROM installations, were obtainable from Microsoft Office Update or as standalone downloads, and required Office XP installation media—these updates could not be uninstalled. Full File updates did not require access to installation media and were intended for network administrators to deploy updates to Office XP users who installed the product from a server location; users could also manually install Full File updates. Full File updates require Windows Installer 2.0; Office XP shipped with version 1.1. Windows Installer 2.0 shipped with Windows XP. On September 25, 2001, Microsoft released Windows Installer 2.0 redistributables for Windows 9x, as well as for Windows NT 4.0 and Windows 2000. Service Pack 1 (SP1) was released on December 11, 2001, and included performance and security improvements, as well as stability improvements based on error reports from users. SP1 also resolved an issue that prevented documents from being saved to MSN Groups. Service Pack 2 (SP2), released on August 21, 2002 included all previously available standalone updates; some of the those previously released included cumulative security patches for Excel 2002 and Word 2002 to address potentially malicious code embedded in document macros. The Full File version of SP2 is cumulative—SP1 does not have to be installed—while the Client version requires SP1 to be installed. Only Full File updates released after SP2 can be applied directly to Client installations of Office XP. Earlier updates were designed to update only administrative images and fail when applied directly to clients. Service Pack 3 (SP3) was released on March 30, 2004, and included all previously released updates, as well as previously unreleased stability improvements based on feedback and error reports received from users. SP3 does not require any earlier service packs to be installed. However, if an Office XP client was updated from a patched administrative