Trevor
In my humble opinion, the windows firewall is not a real firewall because although it can stop unwanted stuff from attacking your computer it cannot stop malware and windows apps accessing the internet (with or without your knowledge).
A good firewall should stop all unwanted internet access to and from your PC, for example, suppose you are already infected with a Trojan or keylogger, these malware can and will contact their criminal originators and the windows firewall will not do a thing to stop it happening. While a proper firewall, such as ZoneAlarm or Norton Personal Firewall, will stop this unauthorised internet contact. That's why you need a proper firewall and not the "mickey mouse" variant supplied by MS.
At the moment, apart from a proper firewall, you seem to have most things covered in protecting your PC. However, depending on how important your PC is to you, you should never become complacent because the criminals out there are always looking for ways to get around and/or incapacitate your protection.
So, to keep up to date, I subscribe to
"Internet Security News for End Users". an email sent out every month by
"Home PC Firewall Gude", at
http://www.firewallguide.com.
Hope this helps.
UK Bob