CSC-SY

I can't have access by any way to the internet.
my dial-up connection always fails after "verifying username and password" with error 720.
I've tried all Microsoft solutions for this problem but still wont work.

I came to a conclusion that my hall networking programs need to be reinstalled but obviously that's can't be done for xp pro (my system).

the main thing is to reinstall tcp/ip service on my system so any one has an idea how to do that>