Cannot connect to internet!

I recently moved, so I switched Comcast regions. Upon
setting up my computer and new Comcast cable modem at my
new residence, I can no longer connect to the internet.
However, I can still connect from my laptop through the
router (which goes through my main computer attached to
the cable modem). All connections are on and stable, and
several hours on the phone with comcast has not yielded
any results. They can see the computer on the network,
but it cannot access the internet. At their
recommendation, I downloaded and applied Winsock fixes,
but none have had affect. What gives?