After purchasing diffractor you can validate your copy of Diffractor using the Buy screen. Click on the Buy menu option to get started (or press F1).
On the Buy screen, enter your purchase email address. When you click the verify button, Diffractor will connect via the internet to confirm your email address. A message will be shown confirming everything went ok (or not).
After validation, you can add additional custom index folders. This is done on the index options screen (press control F6). You will also be able to use locations from Google services.