Microsoft does take security pretty seriously with windows. There have been times they make mistakes, but historically, they are doing better now than they were in the early 2000s before Bill Gates sent a memo noting that they needed to take security seriously. You could argue they take security as serious as any major play like apple and google, seeing they touch a lot of private user data.

[1] https://news.microsoft.com/2000/12/07/gates-offers-new-techn...