Sims 4 from windows 7 to windows 10?

I'm still playing Sims on windows 7 but my new laptop will have Windows 10. I bought the sims 4 base game on CD and the rest through Origin. Can I just download it to Windows 10 or do I have to buy it again?

Just log in to your Origin account and you will be able to reinstall your Sims 4 games as normal. So you do not have to buy anything new.