Hi Al,

From the SP1 sp1readme.htm:

"Limitations on Downloaded Service Packs:
If you download the service pack from the Internet you can apply the service pack only to instances of the Desktop Engine that were installed from sqlrun01.msi. If you attempt to apply the service pack to instances that were created using sqlrun02.msi – sqlrun16.msi from the Setup.exe file that was downloaded from the Internet, you will receive one of the following errors:

This installation package could not be opened. Verify that the package exists and that you can access it, or contact the application vendor to verify that this is a valid Windows Installer package." ...


There's more info in the readme file concerning the setup for MSDE. HTH