How to debug VB.NET COM+ object in VS.NET

Open Component Services

Drill down to COM+ Applications under My Computer

With the COM+ Applications displaying on right side of the screen, click the View menu and then make Status View the active view.

Write down the number in the PID column that corresponds with your COM+ application in question.

Open the Visual Studio.NET solution

Make Solutions Configuration box Debug

Now click the Tools menu option and choose Debug Processes menu option

When the Processes box appears find the PID number from Component Services in the ID column.

Highlight the row and click the Attach button.

When the Attach to Process box appears then check the Common Language Runtime and Script checkboxes.  Click the OK button when finished.

When the Processes screen is active again you will now see a DLLHOST.EXE in the Debugged Processes box.  The ID number should be the same as the one in the Component Service console.

Close the Processes screen to return to the solution screen and the debug process should already be running.

Now set a break point in your code and run the application locally.  Whenever your application reaches that break point it should stop.