I have adjusted my Setup project to install over an installation. This works for as long as I do not have any Windows Service. In my Setup.exe, I have two Windows Services which will be installed. So, the initial installation works well. Then, I go in my Setup project and change the Version. This forces a new ProductCode to be generated. Then, I send those Setup.exe and Setup.msi to the PC. Then, on that PC, we run the new Setup.exe. Because it has been built with a new version and product code, Setup can install over the existing application. But, at the end, when it tries to install the Windows Service, I receive the error:

"Error 1001. The specified service already exists."

Am I assuming correct I am asking too much from the Microsoft Setup?