Applies to these editions of Windows 7

Why am I receiving a message that “Windows has detected unsupported languages files” when installing SP1 RC for Windows 7 or Windows Server 2008 R2?

Service Pack 1 (SP1) RC for Windows 7 and Windows Server 2008 R2 can only be installed on a computer that is running a German, Spanish, French, English, or Japanese version of Windows 7 or Windows Server 2008 R2.