Error Message: Microsoft Windows 2000 Has Detected Software That Is Not Completely Installed on Your Computer (242435)

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SYMPTOMS

When you attempt to upgrade to Windows 2000, you may receive the following error message:

Microsoft Windows 2000 has detected software that is not completely installed on your computer. Windows 2000 Setup cannot continue until you finish installing this software.

To finish the installation process for this software quit Windows 2000 Setup.
Log off of your computer and then log back on again.
Restart Windows 2000 Setup.

The error message occurs again even after you log off and back on as the error message suggests.

CAUSE

This behavior can occur if either of the following registry keys are populated:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnceEx

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Runonce

RESOLUTION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To resolve this issue, use Registry Editor to remove information in the following key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnceEx