Your OS has nothing to do with connection issues beyond whatever firewall it's running by default(in your case, Windows Firewall and most games make an exception for themselves and add it to WF during install).
You need to open up the ports the game uses or just enable UPnP on your router. Putting yourself in the DMZ isn't bad per se when it comes to games, in fact it's probably the easiest method but you are risking some potential security issues.
There have simply been a lot of connection related issues with both the individual game servers and the EA master server, so I wouldn't go doing anything drastic just yet. I've had nights where its stable all night and I've had nights where I get kicked from half of the games or the master server dies for an hour. Just wait a bit, launch time will die down.
Playing: Xenoblade Chronicles DE, Ys IX, God of War
Watching: Lupin, You me and the Apocalypse, Days of Thunder