>I'd like to know which version of Refox is the correct to use with VFP 7.

Refox8 will work, however there is a newer version, ReFox MMII which acutally has a windows interface now.

>A friend told me that I can brand the EXE and DLL togheter and nothing can get my code...

This is simply NOT TRUE! No matter what level of banding you use, with a hexeditor and about 2 seconds of time your VFP .EXE can STILL be decompiled!!!!!!!!!

>How it works? (with VFP 7)

Simple -> it does not.