JSI Tip 9994. Windows does not localize user accounts in the language that you select when you run the Setup program for the Windows Server 2003 R2 Multilingual User Interface Pack if Windows SharePoint Services is installed?

Microsoft Knowledge Base Article 911603 Describes the problem that Windows SharePoint Services (WSS) does not support Multilingual User Interface Pack (MUI) to modify local account security identifier (SID) if Windows SharePoint Services is installed first.