Click the Norton Security icon at the bottom right corner in your system tray. On the pop up window, first check if you have not clicked "Block Traffic" button. As this will block all internet access. If that is ok, maybe the program has been blocked access and has to be unblocked manually. But it was not easy to find where was the blocked list. But here is it location. Go to Norton Internet Security > System and Settings and this is what you see in the image below.
Then you see that the Personal firewall is turned on to protect from unauthorized access to spyware, adware and other unwanted software. Click "Configure" button.
Go to Programs and scroll down the list for Manual Program Control. There you will see the individual internet access settings for each individual program. And you see that [Program name here] setting shows "Block All".
From the drop down list select "Permit All" and now open the desired program.
Now you can scroll through the entire list and individually set the programs to allow and block internet access. Now you may fix some programs not working with the internet which you might have blocked by mistake. You can also set some allowed programs to block. I hope this tip helps. Now figure out the Custom option yourself!
The above was taken from here, and was not written by me.
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