An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Privacy Orientated Linux Operating Sytems we recommend; Qubes: https://www.qubes-os.org/ Tor: http://qubesosfasa4zl44o4tws22di6kepyzfeqv3tg4e3ztknltfxqrymdad.onion/
Subgraph OS: https://subgraph.com/ (not currently available)
Windows 10: Stuck on one of the least private operating systems due to software requirements? try the win10 Privacy tool here: https://www.w10privacy.de/english-home/
Live CD Linux
Privacy Orientated Live CD Operating Sytems we recommend; Tails: https://tails.boum.org/