This is John, a customer advocate at Dell headquarters.

I can't really begin to help you here until I know a few things:

What brand/model of wireless router are you using?
Are you using any encryption? If so, what are you using? (WEP, WPA, etc)
Are any other wireless devices having problems with this network?
Can your laptop connect to any other wireless netoworks? (coffee shops are good places to test this generally)

There are more questions I could ask, but this is a good place to start. I'll do what I can to help!

John
Dell Customer Advocate