We have recently bought a Verizon Mifi 2200. When we plug it in to our home computer (which has Windows 7) it works just fine. When we plug it in to our Dell laptop (with Windows XP) it works fine. But, the Dell laptop will not connect to the MiFi when the MiFi is not plugged into laptop. The MiFi is supposed to be a WiFi spot for laptops! How can I make this work?