My daughter had a problem with her laptop last year -- the WiFi and internal Ethernet just quit working and I couldn't get it working remotely. When she brought it home at Xmas I discovered the problem was an incompletely-removed copy of a 3rd-party firewall. Once I reinstalled and then removed the firewall everything started working again. I had to reinstall it to get the removal software installed.
Sounds to me like you have something similar going on. If the machine once had a Norton/Symantec firewall, the removal process you went through may not have completed properly. Symantec makes a number of removal tools available for troubleshooting this, there are different ones for different versions of Norton Internet Security. Just Google:
http://www.google.com/search?q=norton+removal+tool+[Your_Version_Of_Norton], download the tool that is appropriate for your problem, and try that.
Of course, I shouldn't need to tell you
wink to
create a system-restore point before trying this.