Dynamic Link Library

(D-L-L)

A special file containing resources that can be linked into running programs while they are running (thus, the "dynamic"). Programming routines used by multiple programs can reside in a single DLL file avoiding some duplication.

It is very important, when updating system DLL files, that the installer not overwrite a newer version of the DLL with an older one. Most system DLL files are downward compatible but if a new one is replaced with an old one the expected functions another program uses may not be there. It's also important to maintain system DLL files in system folders and program DLL files in program folders. If system DLLs are in program folders they may be started with the program leading to system interactions hard to diagnose. These and other DLL-related programs fall under the umbrella term "DLL hell."

More Information

• DLL Archive