DLL stands for Dynamic Link Library. It is a shared library which is used for developing software. These files usually have the extension .ddl or .ocx, so when you register the DLL files, the information regarding these files is stored in the Windows registry.
RegSvrHelper is a free, portable and easy to use tool which offers a GUI interface to register/unregister DLL’s. It uses regsrv32, the default windows utility for DLL at the backend. Regsrv32 is command line based, so RegSvrHelper makes the process simple even for the regular users.
Simply browse and select the DLL of your choice and click the Register or Un-Register button.
Download: RegSverHelper
It works on Windows XP, Vista and Windows 7.