It will be better if you could provide some more details. Which Norton program are using- name and version? Did you disable Norton program completely or disable only an individual component like firewall or auto-protect to get Xbox 360 working? If you have disabled Norton program completely, kindly check whether it works when you disable any individual components.
internet security 2009
and the firewall
Try to configure the program rules in firewall for Xbox:
1. Start Norton Internet Security.2. In the Internet section, click Settings.3. Under Smart Firewall, click Configure next to Program Control.4. In the Program Column, check whether the following files are listed and change the Access from Block or Custom to Allow. (If these files are not listed, click Add, find those files, select it and click Open)
Ehshell.exeMcrdsvc.exeSvchost.exeMcxnettw.exeMcrmgr.exeEhexthost.exe6. Click Apply, and then click OK.7. Click OK.
Check the connectivity after this and post the results. If this is not working, you may need to create a general rule in firewall to allow communications through the ports 3074 and 88 which is used by Xbox.