How to support different operating systems in upgrading and new install?
I have a product. The installation is InstallScript MSI type. This produce has two release versions:
Ver 1, Product Code is A, Upgrade code is B
Ver 2, Product Code is C, Upgrade code is B.
In Ver 1, it supported operating system AA, BB. In Ver 2, the requirement is to support OS AA, BB, CC for upgrading from Ver1; For new installation, it should only support operating system CC. So I need to validate the operating system based on the installation mode (upgrading or fresh new install.) If it is fresh installation, the installer will stop user if it is operating system AA or BB.
What is the best way to do this?
What is the right way to detect if the Ver 1 is installed, which has different Product code than the current Version?
