If the trainer runs after this, you need to properly configure your security products (Norton 360 and any other products) to allow trainers to communicate with the internet (please consult your products' documentation for how to do this).
Please note that disabling Norton may not turn off all protection (as this is a safe guard against malware that attempts to do this). Clean Boot Mode ensures that your computer starts up without any of Norton's components being loaded.
EDIT: Norton is notorious for being hard to disable for troubleshooting procedures and you may have to temporarily uninstall it to completely rule out that it is the cause. Once it's confirmed the problem or not, you may reinstall and take the necessary actions if it does turn out to be the problem.
[Edited by Neo7, 9/20/2011 11:25:03 AM]