PDF Reader for Windows 10 is freeware. Upgrade to new versions are free of charge.
If you would like to upgrade to the Pro version (PDF Reader Pro for Windows), you can click from the menu,
Help->Upgrade to Pro
Click Yes, and enter your upgrade code, only if you have purchased one; otherwise, click No to get the information on how to upgrade to the Pro version online.
Benefits of Upgrade
1. Continuous View Mode (show pages continuously without noticeable page break)
2. Book View Mode
3. Facing View Mode
4. Options->Always in 3x Fast Mode
5. Search Text features in Edit->Find Text
6. Enhanced conversion from PDF to other file formats
