MSI Debugger
The MSI Debugger provides you with the ability to step through the actions in your setup and check the values of your properties while your setup executes. The MSI Debugger runs through each action and dialog until it reaches your breakpoint, at which point it halts execution.
To start the MSI Debugger, you must first have a successfully built setup. The release cannot be compressed into Setup.exe for the debugger to work. Once you've built a release, navigate to the MSI Debugger view and click the Go 
button. The debugger runs the setup and returns focus to itself and stops the execution of the setup when it reaches the breakpoint.
Test Your Release
In the Test Your Release view, you can test your newly built setup to make sure everything goes as planned. You have two options here: run or test your setup. If you run your setup, it will perform exactly as if you had double-clicked the setup executable. All files will be installed, all dialogs will display, and all custom actions will execute. If you test your setup, no changes will be made to the target system; only the user interface and any custom actions you have included will execute. This second option is useful if you want to test how your setup looks without taking up further disk space on your system.
See Test Your Release for more information.