Not to worry. The files are there!!!! You just have to tell the Evaluation version of Installshield Express where the files are!!! By default the VFP merge modules are installed to :

c:\program files\common files\microsoft shared\merge modules

There should be a place to set the locations of your Merge Modules under the Tools menu of Installshield Express. In the full Installshield Developer Product it is Tools->Options.

The full Installshield Express product is a good investment if you plan to put out many updates to a product.