VERSION 6 and 7: After purchasing you can activate your copy of Web Designer by entering the serial number. Once it is activated you can download the full template set by clicking on the Download Templates option in the Web Designer Help menu.  

Select to save the file WebDesigner_templates.exe.  Close Web Designer and double click WebDesigner_templates.exe to execute the template installer. Run Web Designer following the template installation and all designs within the Designs gallery will be accessible

VERSION MX 8 and 9: After purchasing you can activate your copy of Web Designer by entering the serial number. Once it is activated simply clicking on a template in the Designs Gallery will download it.