My laptop has a "limited or no connectivity" message when I try to connect to my home network...?

I have WEP security thru my Linksys wireless router. My laptop can connect to outside unsecured networks but I can't fully connect to my own for some reason. My WEP pword is correct and I even tried to add the laptop to my home network using my USB flash via Windows Vista and I still can't connect. Please help! Thanks!