This is usually a firewall issue. Firstly, if you connect through a router, disconnect the router and hook your computer up directly to the cable/DSL modem. if this works, then there is some port-blocking going on in your router that you may need to take care of.

If that does not work, you should open your Firewall and look for the configuration options. Re-add Launcher.exe and Matrix.exe to the list of exclusions and grant them FULL access to the Internet.

Once you have done this, be sure to toggle the Full System Scan from the EULA Screen, and then do it again from the Login screen.