I just bought the DLink  since I got a new computer and wanted the "N" speed.  I am able to connect the new laptop (HP), the Dell (a few years old), but not the Toshiba.  It is probably 7 years old.  The network says it's connected and the connection is excellent, but when I click on IE, it partially loads a page and then says website not found.  If I turned off WPA and have "no security" I can get to the Internet.  I spent almost an hour on the phone with the tech support and basically they said it wasn't the router, but the laptop.  I asked then why does it work with no security and got no response.  This is really frustrating since I can hook up the old router and the Toshiba connects to the Internet with WPA.  
Does anyone have any suggestions what to do?   Do you think if I buy an usb wifi adapter n it would connect?  This laptop only has USB 1.1, would that be a problem?  
Thanks if anyone can help me since I really didn't feel I got much help from tech support.