Thanks for the info. With the information in these posts, I was able to successfully (and silently) install Windows Messenger 5.1 by removing the registry key from messenger.msi using Orca.exe, then packaging it with IExpress using msiexec /qn /i messenger.msi as the setup command, and then putting the resulting file, messenger.exe, into SVC-EXE. That was the last piece I needed to finish my CD.