A Windows XP OEM Preinstallation Kit (OPK) was a package of tools, documentation, and product files provided by Microsoft to Original Equipment Manufacturers (OEMs) and system builders for preinstalling and configuring Windows XP onto new computers for distribution to end-users. The OPK included software like Setup Manager, the Windows Preinstallation Environment (WinPE), and Sysprep, allowing them to create custom installation images with pre-loaded drivers and settings