Step #1 to protect your private data - Have a separate computer, Ubuntu (or some secure OS) installed and disconnect it from the internet permanently. If you want to access any data, just go use the computer and save the data then and there. If you want to transfer data from this computer to another computer, just use a separate encrypted pen drive to transfer between files securely.

If you don't want to use it, just turn it off. I'd love to see how the Chinese/Russian hackers can hack such a machine, unless they have physical access to them.