File Extension DLL


DLL files are dynamic-link library files (sometimes also written “dynamic link library” files) and are an integral part of Microsoft Windows and the software that runs on it. DLL files are shared between a number of different software applications. Each DLL is a small chunk of software code containing instructions and tools for an application to operate a particular hardware device. In the broader sense Microsoft dynamic link-library files sometimes also have the extension .OCX (in the case of files which include ActiveX controls) or .DRV for older system drivers.

The most common problem people will face, with regards to DLL files, is not having them. For example when you plug a new piece of hardware into your PC and you get an error message saying something like “DLL file WXYZ.DLL is missing: please install it now.” What this means is that your PC can’t find the driver associated with the new hardware, because it wasn’t preinstalled with the operating system and you haven’t subsequently installed it either from the CD, accompanying the product, or by downloading it from the manufacturers website.

Like all computer code, a file extension DLL can contain bug and conflict with other software, the result being that problematic dynamic-link library files can compromise the performance of your system by causing crashes and system slow-downs. At the same time some DLLs are updated, for example to add additional functionality, or to accommodate updated ActiveX components. This is why it is important to update drivers and DLLs regularly.

However having modern computers share software components creates threats, as well as opportunities, and these have come to be called “DLL Hell.” Common DLL problems include the incompatibility of a certain DLL with different software, meaning that an application might use one version of a DLL, however, when installed, another application might overwrite that version with a different (or earlier) version of the same DLL causing problems for the older application. Otherwise DLL hell could be caused by erroneous registry entries pointing to the wrong DLL.