The information in this article applies to:
When you install, uninstall, and reinstall programs on your computer, registry keys are created, modified, or deleted. Over time, your computer's registry may begin to contain corrupted, unused, and unnecessary registry keys, especially if keys are not removed when you uninstall a program. As a result, you may begin to experience problems when using OLE to embed objects or Automation to control other programs.
The RegClean utility is designed to clean up unnecessary registry entries in your registry.
The RegClean utility that was originally supplied with Microsoft Visual Basic, version 4.0 for Windows. The Microsoft Office 97 Resource Kit has been updated. The current version is 4.1a.
How To Install RegClean
Copy version 4.1a build 7364.1 of RegClean.exe to any folder on your machine.
How To Run RegClean
Clicking Fix Errors also creates an Undo.reg file in the folder where you ran RegClean. The file will be titled “UNDO computer yyyymmddhhmmss.REG,” where computer is the name of your computer, yyyymmdd is the date, and hhmmss is the time. If at any point you would like to "undo" or put back what RegClean removed from your registry, double-click the Undo.reg file.
The RegClean utility is available for downloading free of charge.
The following file is available for download from the Microsoft Software Library:
~ RegClean.exe (size: 800136 bytes)For more information about downloading files from the Microsoft Software Library, please see the following article in the Microsoft Knowledge Base:
ARTICLE-ID: Q119591 TITLE : How to Obtain Microsoft Support Files from Online Services
What RegClean Does
RegClean analyzes Windows Registry keys that are stored in HKEY_CLASSES_ROOT in the Windows Registry. It finds keys that contain erroneous values, and after recording those entries in an Undo.reg file, it removes them from the Windows Registry.
What RegClean Does Not Do
RegClean does not fix every known problem with the registry. It does not fix a "corrupt" registry; it is limited to fixing problems with normal Windows Registry entries located in HKEY_CLASSES_ROOT.
It is very possible that RegClean will not correct a problem that you have encountered. RegClean will leave any entries in the registry that it does not understand or that could possibly be correct.
FIX: REQUIRES UPDATED OLEAUT32
This error occurred with an earlier version of RegClean. In order for RegClean to work, you must have the updated version of the OLEAUT32.dll. If your system has Internet Explorer version 2.0 or lower, installing Internet Explorer version 3.0 or higher will update the OLEAUT32.dll. If you are using Microsoft Windows NT 3.51 with SP 4 or lower, you will need to install SP 5 in order to update the OLEAUT32.dll. These files are also available for download below. If you experience the below symptoms when using RegClean 4.1a, please follow the resolution instructions.
Two messages boxes appear. One box says the following:
RegClean.exe is linked to missing export OLEAUT32.DLL:421The next message box says the following:
A device attached to the system is not correctly functioning
You need to install the update to the OLE Automation system libraries. For additional information, please see the following articles in the Microsoft Knowledge Base:
ARTICLE-ID: Q180071 TITLE : FILE: Msvbvm50.exe Installs Visual Basic 5.0 Run-Time Files ARTICLE-ID: Q192461 TITLE : FILE: VBRUN60.EXE Installs Visual Basic 6.0 Run-Time FilesPROBLEM: IT DOESN'T SOLVE MY REGISTRY PROBLEMS OR IT JUST CREATES MORE PROBLEMS
(status updated: December 30, 1997)
Running RegClean may, in a few cases, cause other problems, such as causing part of the Microsoft Network viewer to stop functioning, or causing other programs to stop functioning. If this happens to you, simply Undo the changes RegClean made, by double-clicking on the last UNDO.REG file.
These types of problems are very rare, but it's a good idea to keep your last UNDO.REG file for a few days or so.
Microsoft will continue improving RegClean to reduce the frequency of problems like these.
PROBLEM: CANNOT UNDO THE UNDO.REG FILE
(status updated: March 18, 1997)
Windows displays several error message boxes when you try to double-click the Undo.reg file to undo the changes RegClean made.
This problem is unrelated to RegClean. It's a problem with the Associated Program for .reg files.
Use the following steps to correct this problem:
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Additional query words: registry clean update
Last reviewed: October 5, 1998