I just upgraded my PC from Windows 7 to the new Windows 10. Everything looks fine but would like to know if I have to download a antivirus for protection with windows 10 and if so what is a good free one? I had Microsoft Security Essentials with my windows 7 and loved it but not sure if it will work fine with widows 10. Does windows 10 already have a built in antivirus and if so where is that? I've tried looking everywhere and can't find anything. I have Malwarebytes installed but want to make sure I'm protected with a good antivirus. Any help would be appreciated. Thanks.