Virtuemart can be a bit hard to navigate at times and one of our students was having difficulty adding a downloadable product so we created this tutorial for him:
Enable Downloads in the Configuration
Go to Virtuemart >> Admin >> Configuration >> Downloads >> Enable Downloads.
Save.
Add the Downloadable File in the List Products area
Go to Products >> List Products >> click on the image icon.
Note: If you haven't created a product already, do so before this step by clicking "New" in the toolbar of the List Products area.
Upload the file >> change file Type to "Downloadable Product File (to be sold!)"
Configure the rest of the settings appropriately and then Save.