Re: Or... no snooping at all
The better option is to install (say) Linux Mint, then (say) VirtualBox, and finally Windows (your preferred version) inside the virtual machine. Then disable all Windows internet connectivity. Absolutely and finally.
You now have a fast, stable, fully functional PC with an equally fast, stable version of Windows inside it which is available at the touch of a button. Both OSs running simultaneously on the same machine. If Windows ever needs to talk to the internet - why would you ever want it to? - it can do so safely through the host system.