can't surf the web or get my email

[Chris Job]

Hi All

I was having some trouble with my email and my system finally died on
me.  I had to re-install the linux software (Res Hat 5.2).

I can successfully connect to my ISP but can not ping an IP, surf the
web or get fetchmail to poll my ISP's mail server.  I am hoping that you
can give me some suggestions as to what I can do to get things
(espicially my email) working again.  

Thanks for any help
Chris