How to download the files data attached to webform
You can do it by using these modules:

Webform Protected Downloads


  This module provides a handy solution for the following situation:
  
  
  you want to offer some files for download to either anonymous or    registered users
  you don't want those files to be publicly accessible
  you want to collect some data before granting access to the files
  you want to be sure that the user gives a valid email address
  


Webform2PDF


  The Webform2PDF Drupal module is an extension of the Webform module.
  It can be used to generate PDF document from the results of a form.
  The generated PDF document can be attached to the form summary e-mail
  sent by Webform module, or it can be downloaded from the /Results/
  page. Different PDF templates can be set for each form.