Well what I would do is start from scratch. Unplug your internet connection to the router and plug it in your PC and reboot. Check that the internet works properly.
Now take out your router CD, insert it and follow the instructions and verify every tab. In a wireless network, you will have a SSID name and you can have an encryption to protect your network, it could be WEP 64bit or 128bit. When you are going to make the encryption key, all you will need is a paraphrase (family name for instance) and it will generate the key. On the wireless PC, set it up so it will use the channel you will broadcast on, remember the SSID name and papaphrase that will unlock you wireless PC to the AP (access point)