I am using Win XP. I also have installed an anti-virus called AVG (free version). I think Linux provides more security and advance features.
I agree with you ,linux is the one of the best OS by means of securityjulien said:Linux is definitely more secure and provides more flexibility, it is also better if you are a developer, but you won't be up and running in Linux without a minimum of time learning how to use Linux (the good point is that once you start using Linux, you realize it provides gains in efficiency -e.g. cron tasks). The best option for someone already running Windows would be a dual boot solution (both operating systems are installed on your computer and you decide which one to use at the moment you start your computer).