Dependency Walker does what its name implies and _walks_ through your import table looking for DLLs, then through all imports of the DLLs in your import table and repeats this process recursively until it stops discovering new modules.

This is the same thing as listing files/directories. When you find a directory, you open it, and start over the search process from there.

=> Search the import tables, when you find a new DLL, you open that DLL and start hunting for more new DLLs.

Why do you need to find this?