Well for me, Windows 7 64bits too, I can play, launch dual box. For that part it works great.
Now, I cannot log in throught HC launcher. I don't see Shards status, got "error retrieving shard status", and today news don't load.
I tried by desactivating antivirus, autorize through firewall, check malwares... Nothing does the job.
And oh yes, if I close the launcher, I cannot launch it again : "Could not open launcher log file. The launcher may already be running".
I got to kill the processus first to launch it again.
Update: I was thinking something, which ports are involved with HC Launcher? Because here where I live, we have "Shared IP". That means 4 users can share the same IP. Precisely 4 users who don't live in the same place, they just not share the same ports range.. And I know I have just access to ports from 0 to 16383. That could the reason why my HC launcher cannot acces to those informations.