How to clean up invalid registry entries in Visual C++ and in Microsoft Foundation Classes (MFC)

Note Microsoft Visual C++ 2005 and Microsoft Visual C++ .NET 2002 support both the managed code model that is provided by the Microsoft .NET Framework and the unmanaged native Microsoft Windows code model. Part or all of the information in this article applies to managed Visual C++ code and may be applied only by using the .NET Framework.


This article describes the RegMaid utility. You can obtain the RegMaid utility from the Microsoft Download Center (see the "More Information" section).

The RegMaid utility is designed to clean up invalid registry entries that are caused by deleting OLE projects that are created with Visual C++ and Microsoft Foundation Classes (MFC).

More Information

RegMaid provides information about entries that are believed to be problematic within the HKEY_CLASSES_ROOT: CLSID, ProgId, TypeLib, and Interface sections of the registry. This information is in a report form of a list view, where the user can make multiple row selections. Once selections have been made, the user can then delete them from the registry. Although RegMaid does not currently have an Archive and Restore capability, it does provide a printed report mechanism for each of the four views.

The CLSID section considers an entry to contain a problem if any handler or server file entry cannot be found by the system. This can occur if a server has been registered over the net and the network connection has been broken. An entry might also be listed if the server has been moved or deleted. The CLSID section provides the most information about the entry that is listed to help you wisely chose the entries to remove.

The ProgId section tries to match its CLSID entry with one in HKEY_CLASSES_ROOT\CLSID. The typical entry being searched in the registry is of the format HKEY_CLASSES_ROOT\Some ProgId\CLSID. If the entry under HKEY_CLASSES_ROOT does not contain a CLSID sub-entry, then it is ignored. This ensures that only ProgIds are listed. The clean-up process is identical to that of the CLSID section.

The TypeLib section looks for references to .tlb files and if one is found in the registry that cannot be found in the system then the entry is listed as problematic. As with the CLSID section, the files in question are listed.

The final section is the Interface portion of HKEY_CLASSES_ROOT. In this section each entry with a TypeLib entry is compared to the entries in HKEY_CLASSES_ROOT\TypeLib, and if a match is not found, the entry is listed here. This entry has the least amount of information available for deciding which registry entries to delete. In fact, the only information available are the TypeLib and Interface GUIDs. However, because this section is highly dependent on the TypeLib section, it should be safe to delete these entries as long as you have resolved the TypeLib issues first.

The following files are available for download from the Microsoft Download Center:

Visual C++ .NET

Download Download the Regmaid.exe package now.For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to obtain Microsoft support files from online services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.
Note Use the -d option when running RegMaid.exe to decompress the file and re-create the proper directory structure.

Note As of February 10, 1998, there is a new version of RegMaid.exe (version 1.1). It greatly reduces the number of erroneous listings that are caused by RegMaid's inability to find a server file, including:
  • Handling of long file names.
  • Handling of environmental variables in the path.
  • Confusion caused by multiple data entries for the server.


Visual C++ 4.1 Sample: "REGISTRY: Uses the Win32 API to Access the Registry"