Deco, x4 sp2 error

I am new - new to CorelDraw, new to DecoStudio, new to Smart Designer, new to the industry.  Please pardon me, but please tell me, if this newbie question is way off.

It is my understanding that DecoStudio does not come with latest (sp2) of CorelDraw x4.  In order to install Smart Designer, I need to install sp2.  BUT - I keep getting the following error message:

"The update patch cannot be installed by the Windows Installer service because the program to be updated may be missing, or the upgrade patch may update a different version of the program.  Verify that the program to be upgraded exists on your computer and that you have the correct upgrade patch."

CorelDraw x4 exists on my computer.  The full version comes with DecoStudio - right?  I can open it and run it....    I downloaded sp2 directly from the Corel web page, so I don't see how I could have an incorrect upgrade patch.  Help? Please?