How do I install Cloudless File Transfer?

You don't. Cloudless File Transfer is a single portable EXE -- just download it and double-click. There is no installer, no setup wizard, and nothing is written to the registry. Settings are saved in an INI file right next to the EXE, so you can carry it on a USB stick and your preferences travel with you.

To uninstall, delete the EXE (and the INI file if one was created). That is it.