Depending on what browser you're using (Internet Explorer or Firefox) you should be able to disable or unistall the Norton Toolbar by managing your browser's Add-ons.
For Internet Explorer 8:
1. Open Internet Explorer -> Click the 'Tools' menu, and then click Manage Add-ons.
2. Under Add-on Types, click Toolbars and Extensions.
3. Select the Norton Toolbar and click the Disable button.
4. When you are finished, click Close.
5. You may want to restart Internet Explorer (close it down, and reopen it).
For Firefox:
1. Firefox extensions can be uninstalled by going to the Firefox Add-ons manager ("Tools -> Add-ons -> Extensions").
2. Select the Norton Toolbar and click the 'Uninstall' button, then restart Firefox.
3. If the 'Uninstall' option is not working, restart Firefox in Safe Mode and try again. If you still can't uninstall the toolbar, use the 'Disable" option as a workaround.