By default, the paths used in an Advanced Installer project are relative to
the project file. Therefore, when you move the project file you also need to make sure
you move the files used in the project in order to maintain the relative paths.
The type of the paths (relative or absolute) can be changed in the Project Settings tab of the "Edit Project
Settings" dialog. You can get to this dialog by using the "Project" -> "Options" menu
in Advanced Installer. Note that you can also use path variables instead of relative
paths.