A 2nd pc connected to my belkin 54g wirless rouer now mine cannot

Of course you've clicked "refresh" wireless network list? Go to the working computer and in a DOS box type IPCONFIG /ALL to find the gateway address for the router. ( Or refer to your wireless connection utility ). I will probably be 192.168.0.1 for example. In your browser address line put HTTP://192.168.0.1 and click the arrow. You should be talking to the router now, default id and/or password is typically ADMIN. Go to wireless settings and make sure SSID broadcast is turned on. Also note the SSID name, encryption type ( WEP, WPA, etc ) and note the key, if any. You now have enough information to connect the second computer. Yeah, this is complicated. If it's more than you want to know best get a friend to help you, though I may be able to answer specific questions once you get into it.