H2Reg.DLL, H2RegLib.DLL

We also ship a DLL version of H2Reg.exe.



  • H2Reg.DLL contains all the features of H2Reg.exe including the script support. While H2RegLib.DLL is smaller and contains just the basic registration commands.

  • This is a standard 32bit Windows DLL. It does not required ActiveX registration.

  • The DLLs are not as popular as H2Reg.exe. They are typically used by experienced developers who need to code their own installation extensions. We supply example code to get you going.

DLL Functions

  • The following functions are available in both DLLs (the last 2 functions in H2Reg.INI only).

  • See the .pas header file (here) for details of parameters and return codes.

  • The DLLs use the Pascal calling convention. A Demo Test application written in Borland Delphi 6 has been included with the DLL download.


  • GetH2Ver(): PChar - Returns a version string x.x.x.x for MS Help 2. Return empty string if H2 not installed.

  • NSExists(nsName: PChar): Bool; - Returns true if MS Help 2 is found and the given Namespace exists.

  • Reg_Namespace(nsName...): Integer; - Register a Namespace.

  • Reg_Title(nsName...): Integer; - Register a Title under a Namespace.

  • Reg_PlugIn(nsName...): Integer; - Plug a child Namespace into a parent Namespace.

  • Reg_Filter(nsName...): Integer; - Register a filter.

  • UnReg_Filter(nsName...): Integer; - Unregister a Filter.

  • UnReg_PlugIn(nsName...): Integer; - Unregister a child plug-in.

  • UnReg_Title(nsName...): Integer; - Unregister a Title.

  • UnReg_Namespace(nsName...): Integer; - Unregister a Namespace.

  • NS_StartMergeFiles(nsName): Integer; - Merge a Namespace.

  • NS_IsMergeFilesBusy: Bool; - Are we still busy Merging a Namespace?

  • NS_IsMergePending(nsName): Bool; - Does a Namespace require merging?

  • RunScriptFile(file, flags): Integer; - Provides H2Reg.exe scripting functionality.

* Note: The last two items are only available in H2Reg.DLL. They are not included in the smaller H2RegLib.DLL.


Note: The DLL documentation assumes you understand the H2Reg.exe product and its documentation.

The DLL is included with the main H2Reg.exe download.

After installing look for H2Reg DLL code examples under c:\Program Files\Helpware\H2Reg