Glenn lad,
Have you checked your logs (Router or Firewall)? If it is either blocking it, you should be able to see which one, if any, is doing it.
Make sure your IP is correct. Go to start/run/cmd/ipconfig/all and see what comes up. Your internal IP for your new computer may be different from what you think and this should verify it.
There is an answer. We just have to make sure you can find it.
BTW Are you at home now?