I HAVE A DELL COMPUTER,

Question

I HAVE A DELL COMPUTER, AND A LYNKSYS MODEM AND ROUTER. I HAVE TRYED SEVERAL TIMES TO GET THE ROUTER TO WORK SO I CAN USE MY IBM T40 LAPTOP, WIRELESSLY. EACH TIME MY INTERNET ACCESS ON THE DELL IS TURNED OFF, AND I SHOW NO SIGNAL TO MY LAPTOP. I RECONNECT TO THE MODEM ONLY AND EVERYTHINGS FINE ON THE DELL AGAIN. WHAT GIVES??