How To: Register a DLL with a long pathname


Due to a Microsoft limitation, Dynamic Link Libraries (DLLs) with filenames longer than 128 characters do not register correctly with the following methods:

• Running Regsvr32 from Start > Run or the command prompt.
• Compiling the DLL in Visual Basic.
• Using Add from File in the ArcGIS Customize dialog box.


The instructions below include making changes to essential parts of your operating system. It is recommended that you backup your operating system and files, including the registry, before proceeding. Consult with a qualified computer systems professional, if necessary.

Esri cannot guarantee results from incorrect modifications while following these instructions; therefore, use caution and proceed at your own risk.

Instructions provided describe how to register a DLL with a long pathname.

Move the DLL to a path that has fewer than 128 characters. To keep the DLL in its current location, it is necessary to manually register the DLL using one of the following methods:

• Drag and drop the DLL onto \\WINNT\System32\Regsvr32.exe.
• Right-click the DLL and select Register from the Windows Explorer context menu.

[O-Image] Register_in_Menu.reg Utility
If the Register option is not available on the Windows Explorer context menu, add it by running the registry script C:\Program Files\ArcGIS\DeveloperKit\Tools\Register_in_menu.reg.