at&t router not detecting linksys 2 4 ghz in laptop

[thelynna]

at&t router not detecting linksys 2 4 ghz in laptop -- laptop can connect everywhere but my home -- other laptops and notebooks in house are connected

 

[RealBeast]

What OS is on the laptop? Assuming it is a Windows machine, if you open the command prompt box (in accessories folder in the program list) and type "ipconfig" what information is returned for the machine ip address and the gateway address? Is that the same gateway address that the other computers show?