Wireless connects to modem, but not internet

Hello,


I have a Toshiba Satellite M505-S4940. My wireless card, modem, & internet were working fine. We switched internet providers, my sister's computer was connected to the wireless modem and her internet is still working just fine. I never tried my wireless card, but the first time I connected to internet, I connected with an ethernet cord and the internet worked fine. Now if I try to use the internet with my wireless card it only connects to google.com or gmail and that's only from time to time.

The ethernet connection still works and my sister's connection works, so I don't think the modem is the problem. I've used wifi at a local cafe and didn't have any problems with my wireless card, so I think my wireless card is functional.
My MozillaFirefox is set to auto-detect an internet connection. My computer says my wireless card is connected to my modem and it has an "Excellent" connection.

I am at a lost and would appreciate any help whatsoever!


Thank you soooo much!