I know this may sound radical, but as far as I am concerned, the best solution is to replace Microsoft Windows with GNU/Linux rather than to keep trying to make the square peg (Bitcoin) fit into the round hole (Microsoft Windows).
And even if linux is "more" secure on avg, you still have to take into account with the human factor. Humans make mistakes quite frequently even if they are tech savvy, let alone the people with avg or sub avg tech skills.
And let me digress on the "secure", I really lost confidence in the security of software in general, be it Linux, *BSD, etc etc
After Snowden revelations and the various bugs that had been discovered lately (heartbleed ssl hole just to name one) the only thing I personally trust is a paper wallet created on a pristine offline computer.