Hi, I was wondering if anyone could give me a definitive explanation of these 2 codes and especially when I should change either of them.
I'm confused because the help for Upgrade Code says that it "... should remain the same for all versions of a product".
The help for Product Code says "... changing the Product Code after you have already distributed your release is not recommended".
So it seems that neither of these codes is supposed to change, however it's impossible to install a new version of a product if these codes are unchanged. Windows Installer says it's already installed and you have to uninstall it first.
Changing the Upgrade Code only fares no better, I get the same message from Windows Installer.
If I change the Product Code and leave the Upgrade Code the same as the previous release it installs perfectly. This seems to be the only way to get a new release to install, so why does help say that changing this code is not recommended? :confused:
Which codes need to be changed depends on what else you are trying to change in each subsequent package delivery, as well as whether you want to replace or allow side-by-side installation of different versions. These are Windows Installer concepts, so the following articles may help you figure out what you need to do; just remember that the Express edition doesn't always make all the options available.
Typically one always replaces previous versions when one changes just the minor version numbers, and these cases work well with minor upgrades (which Express makes available only through patches). Sometimes "major" versions can be installed side-by-side (like versions of InstallShield, where the Major Upgrade is omitted) and sometimes they replace the previous version (using a Major Upgrade, behavior like most web browsers); in both of these cases a major version number is usually changed.
