Is there a way to add a function where the installer checks whether a specific file exists before continuing the installation?
Here's an example:
1. We create a regular application installer. It installs "app.exe" and several other files to a specified folder.
2. We then want to create a DLC package that adds additional files into the installation folder, but requires the previous version to already be installed in the specified folder.
3. The installer checks whether the "app.exe" file already exists in a specified location. If not, it displays a message, something like: "The setup cannot continue because the required files could not be found in the installation folder."
This is to create an offline executable DLC/update package, not the online automatic update like with Visual Update Express.