PhotoModeler is installed by running the installation executable (usually from a download). The executable has a name similar to PhotoModelerStandard_Setup.exe or PhotoModelerPremium_Setup.exe. (Note there are also update installers with slightly different names that carry out a similar function but for upgrading existing versions).
Locate this file in Windows Explorer and double click. This will start the installation process. In most cases, following the default steps will be sufficient.
At the end of the installation, PhotoModeler will automatically run to complete the setup process. PhotoModeler recognizes when it is run for the first time and carries out critical final installation and setup steps.
See PhotoModeler Activation which is the next step in completing the setup of PhotoModeler.