How can I reinstall Windows 10 (updated from 7 then 8) if I don't have the install CD?

[rodion15]

I installed Windows 7 originally. Later I updated it to 8 and 8.1. I lost the original Windows 7 disc. Is there a way to reinstall Windows 10 now? I have it bloated with adware etc.

 

[Cycloid Torus]

ISO https://www.microsoft.com/en-us/software-download/windows10

 

[rodion15]

Thanks a lot, this is the right one though:
https://www.microsoft.com/en-us/software-download/windows10
(the one you gave me is for Windows 8.1)