May i ask what exactly is the system in question used for? This should be the very first thing any user asks before recommending or giving advice, as it will make all the difference.
Do you use the system as a main hub on your network, do you have multiple devices on that network, if answer is yes to those 2 questions, then you may want to think about a 3rd party application with network monitoring and protections.
If it is the only system you have, and you use it mainly for light surfing, email checking ect as most average users, then yes, windows firewall is enough.