For those who want a legal, no-emulator solution: Kamen Rider Climax Fighters is occasionally available on the (formerly PS Now) cloud streaming service. However, this requires:
, other titles in the franchise have made their way to the platform: SD Shin Kamen Rider Rumble This beat-'em-up title is officially available on Kamen Rider: Climax Scramble The 2018 sequel to Climax Fighters was released as a Nintendo Switch exclusive Gameplay Highlights Online Battles: Kamen Rider Climax Fighters Pc Download
Kamen Rider Climax Fighters was never released officially for PC. It is a PlayStation 4 exclusive title released by Bandai Namco Entertainment in 2017. For those who want a legal, no-emulator solution: