The Inventor SDK is installed by default when you install Inventor. It contains additional sample programs and tools to use when programming Inventor. The SDK is installed in the following location: C:\Users\Public\Documents\Autodesk\Inventor <version>\SDK
When installed, the SDK folder contains three files; DeveloperTools.msi, UserTools.msi, and SDK_Readme.htm. To access the SDK information you need to install one or both of the .msi files, that can be installed by double-clicking the .msi file in Explorer.
The UserTools.msi file contains several add-ins and standalone executables that help automate certain tasks for Inventor users that are not available in the Inventor product itself. When this component is installed, it creates the directories for the tools that include add-ins and standalone executables. The dll and exe files are installed so you can immediately use the tools without having to compile any source code. The source code for the tools is also installed which you can use as a sample and also can modify to change and extend the behaviour of these tools.
The user tools installer includes the following add-ins: DrawingTools, GeneralTools, DerivedPart_SP and AutoCustomize. It also includes the following standalone executables: ColorSchemeEditor, CopyDesign, PartNumberModifier and UpdateThreadDesignation. A UserTools subdirectory is created in the SDK folder and the programs are installed there. For more details regarding these tools, please refer to the individual "ReadMe.txt" file associated with each tool.
The DeveloperTools.msi installs additional sample programs and some tools intended to help developers write applications using the Inventor API. When this component is installed, it creates the directories that contain the DeveloperTools sub folder which contains the following subfolders.