If you are able to ping google.com but internet explorer won't access the internet, you can try installing firefox via ftp
(Note: This tells you 3.0.1, it will work if there is a new version, you just won't be getting the newest version)
WIN+R
Code:
CMD
cd desktop
ftp releases.mozilla.org
Username: Anonymous
Password: im@home.com
Code:
cd pub
cd mozilla.org
cd firefox
cd releases
cd 3.0.1
cd win32
cd en-US
;Remember to use the right case
Code:
bin
;switch to binary
Code:
get "Firefox Setup 3.0.1.exe"