Firewalls that apparently don't exist

[mitchables]

Yeah, for some reason when I connect to the 'net on my PC now (I'm on my olds' computer), every time I try and connect to MSN or look at a webpage, it tells me that apparently I'm behind a firewall that doesn't allow direct connection to the internet.

I don't know when it was activated, because it worked last night. I can't find any active firewall. The Internet Connection Firewall that Windows has is disabled. I even tried disabling my PC-Cillin Firewall but that's never been a problem before.

I can't find this stupid firewall anywhere, and I don't know when it was activated or even HOW it was activated, being that somehow it appeared between me falling asleep and me waking up.

HELP AN AUSSIE OUT.