Lost Web Browsing Capability

Hi, all.

My daughter has suddenly lost her ability to access the Web on
her XP system. She is using a dial-up connection, and even though
the connection seems to be successful, accessing any Web page
results in a time out.

Assuming that the problem was with PeoplePC, I dialed in to my
own ISP, but the result was the same. I tried to ping and
traceroute several sites, but was unsuccessful in every case. My
son-in-law claims that he was able to get an IM connection when
connected to PeoplePC, but I was unable to get it to work myself.

I did upgrade both Adobe Reader and ZoneAlarm Internet Security
the other day, and it's possible that Windows updates were
installed. I ran a system restore as far back as I was able, but
it didn't help. I also turned off ZoneAlarm and switched to the
Windows firewall, hoping that might make a difference; it didn't.

What could be causing this problem? Can anyone give me any
troubleshooting ideas?

Thanks in advance.

--
Keith