if you are serious about security of your puter:
1) Do NOT use windows, use linux only. If you absolutely need windows set up a dual boot and never do anything confidential on windows
2) Learn to use partition encryption and use it to store anything confidential on all of your devices.
3) Never install any dubious software on your puter (including browser extensions)
4) Never access confidential info on an unsecure device (like any smartphone)

ah, and: