my laptop is not connecting to my broadband Motorola wireless router; I've got Intel ProSet 10

During the last few days my laptop is not connecting to my broadband Motorola wireless router; I've got Intel ProSet/Wireless 10.1.0.3 installed in my Dell Latitude D820.  My roommate is experiencing the same situation with his Compaq wireless connection.  However, another roommate who happens to has a Mac G4 is connecting wirelessly to the same router.  The two of us, with PC, tested our connectivity to our neighbor wireless connection and our system connected without any problem. Also we were able to connect to our router using a network cable (Cat 5).  What do you think is the problem with our wireless connection?

 

I really appreciate anybody assesment to this issue.

 

Thanks,

 

Hannibale