Windows Vista build 5421

Windows Vista build 5421 is a pre-RC1 build of Windows Vista. A screenshot of this build was shown in a MSDN blog called "User Account Control Prompts on the Secure Desktop". It demonstrated the User Account Control and its effects on the user. The blog later replaced the image of the build with a copy from build 5381, however Polish website WinBeta.pl archived the image before it got replaced.