The answer depends on the security requirements of your network and what the individual computers are used for.
Actiontec modems and routers have a Stateful Packet Inspection (SPI) firewall built-in, and because of this many users wonder if it is safe to uninstall their PCs software firewall, if it is a third party product, or disable it if it is built into the operating system. This is desirable because when customers purchase a router, they are interested in networking their computers, and having a separate firewall on each PC can make networking quite complicated.
The short answer is Yes, the software firewalls can be removed or disabled, but not without risk. Many operate with only the one firewall on the router successfully for some time. The risk is if a virus or hacker gets past the routers firewall, there is nothing to stop it from compromising the entire network. If this type of arrangement is going to be used, any sensitive information, POS (Point-of-Sale) machines, or PCs used for banking, should be off of the network, or these individual computers should continue to have their own software firewall to protect them if the network was compromised.