DLLs, or dynamic link libraries, are like the building blocks of Windows. Shared DLLs  are basically DLL files that are shared between many different apps. Additionally, there are many common DLLs that are used by most, if not all, Windows applications.

Your Windows Registry includes a path to each of these DLLs, whether the DLL is used by none, one, or many applications. If a particular DLL gets moved or deleted, or an app gets uninstalled incorrectly and the DLL is not removed correctly, or a DLL becomes corrupt, the path to such Shared DLLs in the Windows Registry becomes invalid, and the other applications that share that file cannot find it.

It’s a pretty common problem to run an application you haven’t used in awhile (or a new application) only for it to fail because of a missing DLL. This is something that Registry Reviver can fix. It will make sure all the paths to the DLLs in your system are correct.