Windows Driver Kit: Driver Development Tools
Checked and Free Build Differences
The two distinct builds of the NT-based operating systems that are available are the following:
- The free build (or retail build)
- The free build of Microsoft Windows is used in production environments. The free build of the operating system is built with full compiler optimizations. When the free build discovers correctable problems, it continues to run.
The distribution media that contain the free build of the operating system do not have any special labels—in other words, the CD that contains the free build is labeled with the Windows version name, without any reference to the type of build.
- The checked build (or debug build)
- The checked build of Microsoft Windows makes identifying and diagnosing operating-system-level problems easier.
The checked build differs from the free build in the following ways:
Distribution media that contain the checked build are clearly labeled as "Debug/Checked Build." The checked build distribution medium contains the checked version of the operating system, plus the checked versions of HALs, drivers, file systems, and even many user-mode components. For information about obtaining this build, see Obtaining the Checked Build.
Because the checked build contains fewer optimizations and more debugging checks than the free build, the checked build is both larger in size and slower to run than the free build. As a result, the free build is used in production environments unless it is necessary to use the checked build to identify serious problems.