Try going to Network and Sharing Center at the top of the screen there is an image of a computer, next to it should be an image of a home (if connected to home type network), a building (if connected to work type network) or a park bench (if connected to a public type network). Next to the second image should be a globe representing the internet. You probably can't see all three images.
Under that is a "Connect or Disconnect" link, press the link and complete wizard selecting Home Network in the wizard. When the wizard completes you should see all three.
It looks like you may be connected through the other pc!
1. Go to Change Adapter Settings.
2. Right click "Local Area Connection" > Properties.
3. Click Internet Protocol (TCP/IPv4) > Properties.
4. Select both Obtain Automatic an IP/DNS Server Automatically >Apply >OK
You should then be assigned a new IP from your router and all will be OK!