.DLL File Extension

A DLL file is a compiled library that contains a set of procedures and/or drivers that are referenced and executed by a Windows program. It allows multiple programs to access shared functions through common libraries. DLL files are "dynamically linked" into a program at runtime, meaning they are only loaded as needed.

Many DLL files are provided with the Windows operating system, and others are included by Windows programs. They allow various program functions, such as communication with external devices and hard disk input and output. They may also be referenced by Mac cross-platform applications.

Deleting or modifying the contents of a DLL file may cause errors within the program that references the file. For this reason, DLL files generally should not be opened or edited. However, if an application tries to access a dll file that has been corrupted or is missing, that program will no longer work. In this case, installing a new version of the DLL file may be the easiest option.

DLL-Files.com Client can fix DLL errors.

mfc42u.dll - A Microsoft Foundation Class (MFC) library required by some Windows programs to run. This DLL is included with Windows XP, Windows Vista, and Windows 7 and is most often located in the C:\Windows\System32\ directory. If you try to open a program and Windows reports that you're missing mfc42u.dll, likely your Windows installation has been damaged. You can use a system restore point or your factory system repair disc to fix the issue. Other related files include mfc42u.dll, mfc40.dll, and mfc40u.dll.

mfc80u.dll - An MFC library required by some Windows programs created with Visual C++ 2005. If you're missing this file, you can install the Microsoft Visual C++ 2005 Redistributable Package to install it. Programs that use this DLL generally install it because it is not included with Windows by default. Other DLLs installed with the package include msvcr80.dll, msvcm80.dll, msvcp80.dll, mfc80.dll, mfcmifc80.dll, and mfcm80.dll.

mfc90u.dll - An MFC library required by some Windows programs created with Visual C++ 2008. If you're missing this file, you can install the Microsoft Visual C++ 2008 Redistributable Package to install it. Programs that use this DLL generally install it because it is not included with Windows by default. Other DLLs installed with the package include msvcr90.dll, msvcm90.dll, msvcp90.dll, mfc90.dll, mfcmifc90.dll, and mfcm90.dll.

mfc100u.dll - An MFC library required by some Windows programs created with Visual C++ 2010. If you're missing this file, you can install the Microsoft Visual C++ 2010 Redistributable Package to install it. Programs that use this DLL generally install it because it is not included with Windows by default. Other DLLs installed with the package include msvcr100.dll, msvcm100.dll, msvcp100.dll, mfc100.dll, mfcmifc100.dll, and mfcm100.dll.

Web page generated dynamically when accessed by a user; may incorporate server-side scripts, such as Perl or VB scripts that generate the HTML for the Web page.

Web pages with DLL file extensions are typically hosted on Microsoft IIS Web servers. The DLL extension must be mapped to the correct scripting engine on the server in order for the page to be processed correctly.