InstallShield 2009 Basic MSI: File Not Replaced After Upgrade with New Setups(1 file replaced)

Question

InstallShield 2009 Premier, Basic MSI project

1. I have installed the setup, its installed.
2. I replaced a dll with a newer one and again prepared the setups(didn't change product code or any other code)
3. Now running the new setups, it asks for upgrade
4. I choose upgrade but after completing the setup I notice the dll is not replaced !!!

why and How to solve this?

Answer 1

Did you change the file version of the newer dll to be a higher version than the previous dll? The new dll has to be versioned higher than the older one in order to be replaced.