.NET Automation C#.NET

Regasm 64bit or 32bit through Windows Installer in Visual Studio

Well, nothing much to say, this article is taken from Thanks Leon, just for my own bookmarking here are step. [Article is taken as it is from Leon’s article.]

Realising that I couldn’t be the only person who’s having this problem, I’ve decided to share the code to assist others. All you need to do is follow the below steps:

  • In your main project (the one containing the class you want to register), right click the project file and select Add / New Item and select Installer Class. Call it something like clsRegisterDll.cs
  • In the designer that appears, click ‘Click here to switch to code view’ or right click the clsRegisterDll.cs file in solution explorer and select View Code
  • Replace the code in the window with the code listed below, and make sure you change ‘YourNamespace’. This has to match with the namespace in the clsRegisterDll.Designer.cs file.
  • Compile your project
  • In your installer, make sure you have added your dll to the Application Folder, and then right-click the installer project and select View / Custom Actions
  • Right-click Install, and then click Add Custom Action
  • Double click on Application Folder, and then on your dll
  • Do the same for the Commit action
  • Build and test your installer
  • You should now have an installer that registers your dll using regasm /codebase.


using System.ComponentModel;
using System.Configuration.Install;

namespace YourNamespace
public partial class RegisterDll : Installer
public RegisterDll()

public override void Commit(System.Collections.IDictionary savedState)

// Get the location of regasm
string regasmPath = System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory() + @"regasm.exe";
// Get the location of our DLL
string componentPath = typeof(RegisterDll).Assembly.Location;
// Execute regasm
System.Diagnostics.Process.Start(regasmPath, "/codebase \"" + componentPath + "\"");

public override void Install(System.Collections.IDictionary stateSaver)


.NET Automation C#.NET VB.NET/VB

Excel Automation Add-In for Office 64bit Check List

After days of research, hit and trail; today I finally got a working 64bit Excel Automation Add-In. I am using Visual Studio 2010 [.NET 4.0 client profile framework]. 

1. Create a Project using Visual Studio Office 2010 template “Excel 2010 Add-In”. [I opt for this as I need Ribbon UI too, if you don’t need that you can use Class library project as well]

2. Create a New class and follow this article from Eric ( Excel Automation AddIn in Visual studio ). This article covers 95% of stuff you need it to work. Thanks Eric your article is still valid after 3 yrs and new version than those mention there.

3. Make sure you, have a Signed Assembly. I am not sure if it is really true, but when I was manually registering my assembly in failed cases, it warn me to sign them, though it says “registration succeed”.

4. Good thing is I am creating Add-IN using 32bit machine, and even though my addin works for 64bit. I do not define any specific CPU, just use ANYCPU flag where applicable.

5. Make sure you do not check “Make COM Visible” under Advance setting of your Assembly properties. Again I am not sure, if it is true, but it works when I have it OFF.

6. Do not check “Register for COM” under the BUILD Tab of Project property in Visual Studio. We need to manually register using 64bit regasm through our Setup or command line as you like.

7. [Guess not important or relevant], I have by default Sign for ClickOnce mainfest enable. Actually it is enable for Template project by Visual studio. I keep it that way, doesn’t harm to have it.

8. Make sure to create a good GUID for Class definition as define in article. There is another GUID used in Assembly information, I try to match them and it didn’t work. When it works they have different GUID. Though have it same or different should make difference according to me.

9. I define a ProgID on top of my class like

public class Sound



I guess that is all what I make changes and have it working. Best of luck.