WindowsBuild

The installer sets this variable to the Windows build number of the target system, as follows:

*The build numbers given for Windows 10 and later, including their Server counterparts, include pre-release versions. Furthermore, due to Microsoft's new policy of "Windows as a service", each new public release has a different (higher) build number than the previous, while retaining the same 10.0 major.minor version number. Please consult online sources for the exact build number corresponding to a particular public release if you need to distinguish between them.

Usage

You can refer to it as <WindowsBuild>. In conditional expressions you can omit the brackets and use tests like (Version9X = 410) AND (WindowsBuild >= 2222). Do not set this variable directly; it is set automatically when the installer runs.

For Windows 10/11 and Server 2016-2025 the best way to check for a particular version is to use a combination of the following variables, one from each group:

1. VersionNT, VersionNT32, VersionNT64 as required (Server editions are always 64-bit, but Windows 10 may be x86 (32-bit), or x64 or arm64 (64-bit))
2. WindowsBuild if you need to distinguish between releases
3. WindowsType, MsiNTProductType, or any of the other MsiNT... variables if you need to distinguish between product subtypes

For earlier Windows versions the build numbers are not the most reliable way to distinguish between various Windows editions. For them, it's better to use a combination of the following variables, one from each group:

1. Version9X, VersionNT, VersionNT32, VersionNT64
2. ServicePackLevel
3. WindowsType, MsiNTProductType, or any of the other MsiNT... variables

Related topics

ServicePackLevel, ServicePackLevelMinor, Version9X, VersionNT, VersionNT32, VersionNT64, System information variables