Windows 10 comes with a really nice Windows defender; unlike previous windows versions this one doesn't need an antivirus to back it up; its pretty effective as well; it has completely kept my Computer from other viruses when i checked it out with BitDefender and Norton; so i decided to just keep it since i dont need a license and keep paying like other antiviruses
I love this antivirus as well; i just got Windows 10 yesterday and i can agree with this guy that the security of the Windows Defender is really amazing. I like updating it everyday just for the fun of it. Windows 10 has really made my day and i can start loving to use this operating system being safe and sound.