I installed it into my new computer that has windows 10 and it wont launch probably because of old software. I have the registration code so is it possible to get the digital version free and put the code into that version.
If it is the original game, there's a good chance Windows 10 won't play it. The latest version of Windows prevents games with secuRom and SafeDisc games from playing for security reasons, which a good portion of games from the 2000s have.
As for the registration code, I'm no sure if you are talking about the product key to the original game. If the product key is to the original game, then it's not possible. You would have to buy a digital copy through Origin or Gog.com to play it on Windows 10.
I had the same problem- I could not rum Sim City 4 on windows 10 so I obtained the game through Origin. When I launch through origin, a box apperas asking if I want to let the app make changes to my computer. Whether I say 'yes' or 'no' nothing happens and the game won't launch! Any ideas out there?