* Missing, corrupt, or damaged DLL.
* Overwriting or deletion of one or more DLLs during program install or uninstall.
* Faulty or corrupt application programs.
* Malware infections.
* Erroneous or false entries in the registry.

To understand DLL errors better, lets have a look at some common DLL errors and the methods you can use to fix them. Here are some most common:

Msvcr71.dll Error

The Msvcr71.dll file belongs to the Microsoft Visual C Runtime library 7.1 engine that is required by Microsoft C++.NET-based Windows applications, such as Microsoft Windows Office versions 2002 and 2003 and Microsoft Visual Studio.NET versions 2002, 2003 & 2005. These applications require the Msvcr71.dll file to execute operations such as including the functionality for drop-down menus, toolbar buttons, and scroll bars, and to control mouse operations.

Msvcr71.dll errors usually occur when the DLL file is damaged, deleted, or overwritten due to installation or removal of an application. The file may also get affected if there is a problem with an application that uses it. Additionally, registry problems and virus infections may also generate Msvcr71.dll errors on the system.

When the error occurs, error messages similar to the one displayed below may appear on your desktop.

The application has failed to start because MSVCR71.dll was not found. Reinstalling this application may repair this problem.

Program_File failed because MSVCR71.dll was not found.

Msvcp71.dll Error

The Msvcp71.Dll is another Microsoft C Runtime library file which is required by several Microsoft and non-Microsoft applications to perform several operations. Errors linked to the Msvcp71.dll file may occur if this file is broken, damaged or gone from the system due to incorrect program install/uninstall, virus infections, and registry troubles. When the Msvcp71.dll error occurs, you may see error messages similar to the following:

This application has failed to begin because Msvcp71.dll was not found. Re-installing the application may repair this problem.

Msvcp71.dll is a bad windows image. Please check against your installation diskette.

Shell32.dll Error

The Shell32.dll is a Windows library file that contains the functions required by Windows Shell API. This DLL file helps with operations such as opening files and Web pages on your PC. Most commonly, Shell32.dll errors occur while launching the Internet Explorer Web browser or while creating or accessing a folder in Windows Explorer. These errors usually occur due to problems in the registry.

When a Shell32 error occurs you may receive an error subject matter, similar to the one given below:

This program has performed an illegal process and will be shut down.

Details:

Program_File caused an invalid page fault in SHELL32.DLL

The error message will close by prompting:

There was an internal error and one of the windows you were using will be closed.

Msoe.dll Error

The Msoe.dll is an essential file required by the Microsoft Outlook Express application. The Msoe.dll error usually occurs due to a missing Address Book (.WAB) file, or due to the existence of two versions of Outlook Express on the PC. When the error occurs, an error message like to the one given below maybe displayed on your screen.

Outlook Express could not be started because Msoe.dll could not be loaded”

Most of the time, this error can be answered by reinstalling the Address Book Windows element or by completely taking out Outlook Express from the system and then installing the Outlook Express version you need on your system.

Simple Tips to Prevent and Fix DLL Errors

To fix the msvcr71.dll error and other DLL errors and prevent them from happening on the system, you can follow some of the tips while working on your PC.

* Be careful while installing and uninstalling applications and do not overwrite or erase shared DLLs that maybe required by other programs on your system.
* Keep Off installing unsolicited, freeware applications that are likely to contain malicious and harmful codes.
* Save your operating system, software programs, and device drivers up-to-date with the latest service packs, patches, and security releases.
* Perform regular registry scan and fix with the help of a reliable and effective registry cleaner tool to ensure that registry problems do not cause errors on the system.
* Maintain your antivirus and antispyware tools updated with the latest virus definition and schedule periodic complete system scans to ensure that your system stays free from malicious information