Error message when you try to install the certification authority role on a Windows Server 2008-based computer: "Cannot install Certification Authority"

On a Windows Server 2008-based computer, when you try to install the certification authority (CA) role, you receive the following error message:

This problem occurs in the scenario when only the CA Web Enrollment service was installed previously under the Active Directory Certificate Services (AD CS) role, and then the CA Web Enrollment service was uninstalled. In this scenario, the following registry subkey still exists in the registry: However, this registry subkey should have been deleted.

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: To resolve this problem, check whether the following registry subkey exists:If this registry subkey exists, back up the registry subkey to a file, and then delete this registry subkey. Then, you should be able to install the CA role.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.