DLL stands for Dynamic Link Library. These are files that are commonly used by various computer applications within the operating system as well as third-party software programs. Since these DLL files use processes that are common in nature and are frequently used by different software, it makes sense to have these files that can be called on to perform that process instead of having multiple files within each application folder.DLL files were critical in the days when space was a concern and many experts feel that the DLL files may have outlived their usage. Even so, DLL files continue to be used by application manufacturers as they are convenient and at the same time make applications faster.DLL files like any other files are vulnerable to errors due to various reasons that could lead to broken, corrupt, missing, invalid or incompatible files. When you come across a DLL file error, it is important that you know the steps to resolve them yourself.Missing file errors, such as “Msvcr71.dll cannot be found.” occur if the DLL file generating the error is overwritten by an older version when you install a new software or is removed when you uninstall an existing software. If the error occurs after you have installed a software, try to search for an update for this software to resolve the error. If no update is available, try to search for the recent version of the DLL file on the Internet and other PCs with same configuration. If you find the file, replace it on the PC to see if the error goes away, but remember to backup the existing file before replacing it. If nothing works, use System Restore to revert your PC configuration to the time when it was free from problems. If the error follows a program un-installation, reinstall the program to replace all the files removed to repair the error. If you remove the program again, remember to retain the shared DLL files that generated the error.To make it possible to have multiple versions of the same files on the PC, Microsoft uses the manifest feature in applications. This feature enables side-by-side existence of different versions of the same file, such as msvcr80.dll in the WinSxS folder instead of the default C:System32 folder. Any problems with files in the WinSxS folder may generate DLL errors. You may attempt to resolve these errors by reinstalling the application that generated the error. If this does not work, you may contact the application manufacturer for a solution.Rundll errors and runtime errors may occur if your PC is infected with a virus or a Trojan. To get rid of these malicious infections, it is essential for you to have the latest and robust antivirus tool on your PC. If you think that your PC might be infected with a virus, use your antivirus tool to immediately perform a thorough full system scan and remove all malware from it. To ensure that you are ready to fight viruses when required, remember to keep your antivirus tool updated at all times.Finally, to keep your PC free from DLL errors, it is essential to maintain a healthy registry. You can easily achieve this goal with the help of a good registry cleaner and maintenance tool.