I've used Windows since DOS, and Linux for over 10 years. Though I favor Linux, one of my computers has always been dual booted with the latest version of Windows - there are advantages to having both operating systems available.
Many of the earlier issues with security with Windows, had a lot to do with permissions. If you take Microsoft's modern day suggestions for setup, such as the use of standard accounts, and you keep it up-to-date, and you don't run through the internet naked, you'll be in pretty good shape.
I'm confident in using either one of them, interchangeably, on a day-to-day basis.