need help with PCI DSS compliance

As a small business owner, our credit card processing company is now requiring us to prove compliance with the Payment Card Industry Data Security Standards (PCI DSS) to show we are safeguarding our customers credit card numbers. We have avast 4.8 professional in use. Wondering if this program is already doing some of what we need. Not wanting to pay more for a service we may already have.
Below are the items in question.

1.5 Has IP-masquerading been implented to prevent internal addresses from being translated and revealed on the Internet?
Use technologies that implement RFC 1918 address space, such as port address translation (PAT) or network address translation ( NAT).

11.5 Is file integrity monitoring software deployed to alert personnel to unauthorized modification of critical system or content files?

any information you could provide would be most appreciated.
thanks.

Eh? What has a credit card security to do with Avast!?

No, I don’t think avast! performs these things. Sounds more like a task for a personal firewall to me…?