By Adam Nagy
There are some articles on the steps of creating a Registry Free Inventor AddIn:
Making your Visual Basic Add-In Registry Free
Migrate .Net Add-Ins to registry free
However, a thing worth pointing out is that you could also use the .NET Wizard to do the necessary steps.
If you go on the http://www.autodesk.com/developinventor page then you can download an updated version of DeveloperTools.msi, which also installs Project Wizards for both Visual Studio 2010 and Visual Studio 2010 Express.
After the install, when you go into Visual Studio then you'll find a new project type called Autodesk Inventor 2013 AddIn.
This project will take care of the manifest file and addin file creation, plus the post build setting that embeds the manifest file in the created dll using mt.exe. If mt.exe is not available on your computer, then the build will fail.
Note: mt.exe is not part of the Visual Basic 2010 Express or Visual C# 2010 Express install, but is part of Visual C++ 2010 Express, so one way to get access to that file is through installing that.
Once you saved your project then you can locate its files (default save path is <Documents folder>\Visual Studio 2010\Projects), which also include Readme.txt. This provides you information about where to place the *.addin file and what it should contain so that Inventor will load your AddIn .
Visual Studio 2010 Express does not let you edit some of the project settings, inc. post build steps or startup exe for debug. However, you can edit the project file directly to get around this limitation.
If you close your project and then open up the project file (*.vbproj or *.csproj) in Notepad, then you can add the highlighted lines to it so that when you hit F5 when your project is loaded in Visual Studio then Inventor will be started:
<PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
<StartProgram>C:\Program Files\Autodesk\Inventor 2013\Bin\Inventor.exe</StartProgram>
You can find more detailed information about this in the Autodesk Inventor 2013 API Help (C:\Program Files\Autodesk\Inventor 2013\Local Help\admapi_17_0.chm) under Inventor API User's Manual >> API Overviews >> Creating an Inventor Add-In