Most virus checkers will block wireless, so if all else fails, turn off the firewall. Enter the router and make sure it is set to work with wireless by typing 196.168.2.1 on your browser. This will reset the router to defaults, however, your wired system will still work. Leave it unplugged for at least two minutes. If it still doesn't work, go back to the router and pull the power plug. With your key turned off, if your laptop won't connect, make sure the network switch is turned on and also try to make sure your laptop will connect to some unsecured (or secured) network, possibly a friend's. When troubleshooting wireless problems, always turn off the WEP or WAP key until you can see your laptop on the client list.
If you have a working computer wired to the router, you should see at least one client. Go to the tab or button that says, 'clients' and see how many clients there are. Check all the little things you can look at and make sure they look right. Open up the router by typing 192.168.2.1 on your browser. In such cases, wire works but wireless doesn't. If the power goes off to your router, all the little knobs and buttons are likely to reset.
