The offline registry library (Offreg.dll) is used to modify a registry hive outside the active system registry. This library is intended for registry update scenarios such as servicing an operating system image. The library supports registry hive formats starting with Windows Vista.
Developer audience
This technology is for original equipment manufacturers (OEMs), antivirus and antimalware software vendors, and other application developers who must be able to parse registry hive files without loading them into the active registry.
Run-time requirements
The offline registry library is provided as a binary redistributable dynamic-link library (DLL). This library runs on the following versions of Windows:
Windows Server 2016 Windows 10 Windows 8.1 Windows Server 2012 R2 Windows 8 Windows Server 2012 Windows 7 Windows Server 2008 R2 Windows Server 2008 Windows Vista
Applications should link to Offreg.dll using dynamic linking.
Offreg.dll is provided in the Windows Driver Kit (WDK) for Windows 10 and earlier versions of the Windows operating system.
For information about obtaining the WDK, see How to Get the WDK and the WLK or visit the MSDN Subscriptions website.