It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
Right-click on the link and then select Save Link As...
This is a zip file and you will need to unzip and extract all the files in the folder.
Save them to the same folder (this step is important so the IWU license will install and you will have an authentic installation that will not require eventual payment.
Once extracted and saved to the same folder, click on the file with the .MSI extension. This is the Windows installer file. The second file is the license file that will get pulled in during installation of both are in the same folder.
The program will begin installing on your computer.