Every single time when you install StreamInsight, the installer comes asking for a product key. But what if your installers come from sources like MSDN or TechNEt subscriber downloads? Most of the time your installer come with pre-bidded keys and you don’t find a key on you product keys page.
When you find yourself in this situation then all you have to do is (if you haven’t already) mount the DVD/ISO/other SQL Server Installation Sources and navigate to either the x86 or x64 folder and open the DefaultSetup.ini file. all you then need to do is to locate the PID section and there’s your product key :-)