Explanation of Regsvr32 usage and error messages
You can use the Regsvr32 tool (Regsvr32.exe) to register and unregister OLE controls such as DLL or ActiveX Controls (OCX) files that are self-registerable. This may be necessary to troubleshoot some issues with Windows, Microsoft Internet Explorer, or other programs. For example, the following article in the Microsoft Knowledge Base requires that you use Regsvr32.exe to unregister the Wuv3is.dll control before you reinstall it from the Windows Update site:
241122 Application error when you click Product Updates
If the registration of a control is unsuccessful or you have to have developer information about how to troubleshoot unsuccessful OLE control registration attempts, please see the following article in the Microsoft Knowledge Base:
140346 Possible reasons for OLE control registration failure
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB249873.