See these:
Best Practices for Running Symantec Endpoint Protection 12.1 on Point-of-Sale Devices
http://www.symantec.com/content/en/us/enterprise/white_papers/b-best-practices-running-sep-12.1-pos-devices-21274594.pdf
https://www.symantec.com/content/en/us/enterprise/white_papers/b-sol-guide-pci-wp-us.en.pdf