Thanks a lot for the quick response.
I have tested the application and here are the details:
The application works fine with small size directories (up to 2 GB).
When I tried to create stand alone zip files out of a 7 GB directory, only 2 out of 4 zip files were actually created.
Also, when choosing the big directory and marking the "scan subdirectories too?" box, most of the time the application gets stuck and I need to restart it (4 out of 5 times it doesn't work).
I am sure this app wasn't meant to handle such a big size directories, but maybe with some minor changes it will.
I appriciate your help !