A external backup is a good idea,even if your not worried about losing data,picture,ect .and maybe relying on either system restore or refreshing your computer,a external backup is just way better,so much less work,anyway Windows Defender I think should be your first line defense,then MBAM with it if you hate the idea of having paid for it and not using it.Third party firewall( only my opinion and maybe a bad one is Comodo or just windows) and if you are using Comodo really would think twice about uninstalling MBAM. GL