Dynamic Link Libraries (DLLs) are a fundamental part of the Windows operating system. They are shared libraries that contain code and data that can be used by multiple programs at the same time. DLLs can be used to extend the functionality of a program, or to share code between multiple programs. In order for a DLL to be used by a program, it must be registered with the Windows registry.
There are several ways to check if a DLL is registered. One way is to use the Windows Registry Editor. To do this, open the Registry Editor (regedit.exe) and navigate to the following key: