JSI Tip 6578. When a Windows-based computer that is a domain controller is demoted to a member server by using the Active Directory Installation wizard (Dcpromo.exe), you are unable to recover Encrypting File System (EFS)-encrypted documents?

Microsoft Knowledge Base Article 276239 contains the following Description:

When a Windows-based computer that is a domain controller is demoted to a member server by using the Active Directory Installation wizard (Dcpromo.exe), you are unable to recover Encrypting File System (EFS)-encrypted documents. This issue can..."