Ask yourself if you've been using computers and designing software since the early 1980s. If the answer is "no" then it's somebody else...
If you use Windows, you've placed yourself at risk. You don't know what flaws Microsoft has left in Windows and you won't know until you're compromised.
No matter how good you think you are, no matter how good other people tell you that you are, no matter how many times you gotten away with it, if you continue to use a flawed design and think you're safe because you haven't been bitten yet, sooner or later you're going to be.
"We've always done it this way. It's never been a problem before so it's not a problem now."
-- NASA management, January 28th, 1986, about 11AM.
-- Admiral Husband Kimmel, COMNAVPACFLT, December 7th, 1941, about 7AM.
-- Captain Edward J. Smith, RMS Titanic, April 14th, 1912, about 11PM.
-- Maurice Gamelin, French Supreme Commander, Maginot Line, June 4th, 1940