Solution
When LabVIEW finishes to build the installer, you can find the upgrade code by going directly to the registry and searching for the Product ID of that specific program which can be found in the ini generated file associated to the installer. It is going to be under the [
install.msi] section which is the last one in the list of the msi components:
In order to find the upgrade code directly in the registry, you need to go to the following location: HKLM\SOFTWARE\Wow6432node\National Instruments\Common\Installer\Parts. The specific location for a program is labeled with an alphanumeric code, this should match the ProductId. Within the folder denoted by the code, you can find product information including the version and upgrade code: