Wow, was this a pain...the below error was received:
An installaton package for the product Microsoft SQL Server Native Client cannot be found. Try the installation again using a valid copy of the installation package ‘sqlncli.msi’
The history of the install, is most likely the root cause, this was on a application server, we first installed the SQL Native Client and applied SP2. Then we had a requirement for SQL Reporting Services, than of course another new requirement, Integration Services and Work Station components. We were able to bring up the install and select the new components, but then the error above happenned. I think it all revolved around SP2 being applied first.
Some quick research indicated that a possible solution may be to uninstall the SNAC, SQL Native Client, and re-run the setup, selecting the new components.
How to un-install SNAC that was applied with SP2 ? Manuall extract it and then find the sqlncli.msi, execute the msi (double click on it) and select un-install.
This worked for us !