It is an ActiveX wrapper that allows Windows Forms applications to host the Adobe PDF Reader interface.

Do not download DLLs from “DLL download” websites (e.g., DLL-files.com, DLLme.com, Fix4DLL). These sites are unregulated; files often contain malware, are out-of-date, or are built for different Windows architectures (32-bit vs. 64-bit).

In your Visual Studio project, open a Form in . Right-click the Toolbox and select "Choose Items..." .