How do I debug a custom action/installer class?

Here is how you can do debug custom action.  You can try using one of the following methods:

• Add a call in your code to System.Diagnostics.Debugger.Launch. This method opens Just-In-Time debugging and enables you to attach a new debugger to your code.
• Add a call in your code to MessageBox.Show("Debug Me"). When the message box is shown, use Visual Studio to attach to the MessageBox process. Then add breaks (for Visual C# projects) or stops (for Visual Basic projects) in the code.
• Set your debugging preferences to start %windir%\Microsoft.net\Framework\version\InstallUtil.exe as an external program on the Debug Page of the Project Designer. The name of the custom action assembly is the command line arguments. When you press F5, you hit your breakpoint. InstallUtil.exe will run your custom actions just as MSI does.

Life was difficult until i find this solution from MSDN.