Most people actually recommend that you run it in conjunction with Windows Defender, so while it's incredibly reliable, it's probably still not as reliable as you think and/or might need it to be. If you must run Windows for crypto activities, you're going to need to stop risking all of your funds for small freebies like pirated movies, software, etc., as your coins are probably worth more than they are. You have very little room for error, if any at all.