Considering that online game playing traffic requires peer-to-peer connectivity (i.e. it requires UDP traffic to pass through from all destinations, and TCP traffic to all destinations from a host of ports), it is quite likely to get blocked by your firewall unless you have explicitly relaxed its ruleset.

This applies to all firewalls: regardless of whether it is a software firewall (such as the one that are now integrated in the later versions of Windows Operating Systems), a firewall that has been preloaded into your Broadband Internet Gateways' firmware, or a dedicated firewall router.

If you were able to setup and configure your WiFi USB adapter flawlessly but are unable to play games online with others, you may want to have a look at your firewall's ruleset.

Here is How to Determine if Your Gaming Traffic is being Blocked by a Firewall:

If you are unable to login to your 3Com Wireless gear, it may be because you are typing-in incorrect authentication (username/password) details. Double-check your password (if any), and verify that neither the CAPSLOCK key on your keyboard is “On,” nor one of the SHIFT keys on your keyboard stuck in pressed-down state.

Considering that many administrators restrict how (using only wired, terminal, or wireless access), and from where (using filters based on IP addresses, MAC Addresses, or only from select computers) various devices can be configured, it may be quite possible that you are not even reaching the device in question. It may be helpful, therefore, to try to login using a wired (LAN based, or Terminal/Serial Port) access before doing a brute-force factory reset on your 3Com gear.