Occasionally when a user tries to run or install a new program, they may get an error message like like this:

Component “MFC42.DLL” or one of its dependencies not correctly registered a file is missing or invalid

This means that a certain file is missing (in this case, MFC42.DLL). Software developers often assume that the end user has these particular files when creating their software. However, a stock-standard Windows installation doesnt include them and therefor, when you run the new program it complains that the file is missing.

Here are the most common packages that third party software often requests when trying to run. Its probably a good idea for computer technicians to have these handy when going onsite.

.NET Framework Version 2.0
Many modern applications require .NET which is Microsoft’s framework used to help developers.
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.NET Framework Version 1.1
Same as .NET 2.0, just a little bit older.
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Visual Basic 6.0 Runtime Files
Some older applications may require Visual Basic 6.0 runtime files. This package contains the following files: ASycFilt.dll, ComCat.dll, MSVBVM60.dll, OLEAut32.dll, OLEPro32.dll, STDOLE2.tlb, ADVPack.dll, W95Inf16.dll, W95Inf32.dll, VBRun60.inf
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Visual Basic 5.0 Runtime Files
Some older applications may require Visual Basic 5.0 runtime files. This package contains the following files: Msvbvm50.dll, Oleaut32.dll, Olepro32.dll, Stdole2.tlb, Asycfilt.dll, Comcat.dll
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Visual Basic 4.0 Runtime Files
Some older applications may require Visual Basic 4.0 runtime files. This package contains: Vb40016.dll & Vb40032.dll
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Anything Else:
If the missing file is part of the original Windows installation, you can repair it by going to Start > Run and type: sfc /scannow
The System File Checker will scan for damaged or missing files and if it finds any, will replace it with a good version from the Windows CD – so keep a Windows CD handy when using this command.

For non-Windows files, but are still created by Microsoft, you can search Microsofts database where you can type in the filename of the file you are missing and it will tell you what application installed it. You can visit the database Here

For third party applications, DLL-Files.com is a good choice, which you can visit Here.