Many a times I have noticed an error whenever I try to execute a program from path that is Error 1721. To avoid this error simply follow these steps:
1. Create a public property in the property sections of your installer editor
2. Set the path of the property to [SourceDir] or to whatever you wish.
3. Come to MSI Script section and in User Interface tab call action "Set Property"
4. In the new box give a name to your action and specify the public property that has been created by you in step 2.
5. in the value box write [SourceDir]xyz.exe(where xyz.exe is the program that you want to execute) and place this action just after Migrate Feature State.
6. Copy this action and paste the same in Execute Immediate tab of Msi Script just after "Migrate Feature State" action. Then jump to Setup Editor and click on Tables, press ctrl+h this will open up the find and replace window type the name of change custom action in find window and replace it with the original custom action. For example in step 5 you specified "CallSetup" as the name to your action now when this action would be copy/pasted in "Execute Immediate" tab it would be renamed to "CallSetup1", so to show consistency in your program type "CallSetup1" in find window and then replace it with "CallSetup".
7. Come to "Execute Deferred" and call the "Execute program from path" action and place just below "Publish Product" action. In the window type in a name for this action and provide the proprty name(created in step 2) in the property box.
8. Double click on If statement and write this condition in the box REMOVE~="ALL" and press ok , move this if statement above "Execute program from path" action and double click the End statement.
9. Compile and run your msi, it will now run the program from the path you specified.