tl;dr: a free firewall for Windows which blocks everything by default and doesn't alert you when a program fails to go through it - instead, blocked things go i

tl;dr: a free firewall for Windows which blocks everything by default and doesn't alert you when a program fails to go through it - instead, blocked things go into a "recently blocked" list going back up to 2 minutes, where you can explicitly whitelist them. Windows Firewall has pretty bad defaults (e.g. unrestricted outgoing traffic among other things) and its advanced mode is a pain to work with. I've been using TinyWall for a while and it's come to be one of the first things I install on a fresh system. Disclosure: I am not in any way involved with this software nor its author.