Computers can ping network but not eachother?

Two of the computers on my network are refusing to talk to eachother. They can ping out to the rest of the network, get on the internet, and get on exchange, but they can’t ping eachother. I checked the DNS, IP, Subnet mask, and firewall properties on both computers and they are both correct. I also checked the switch that they are plugged into and all of the settings on it appear to be correct as well. I need to get these computers talking to eachother so that they can share a printer and it is rather important that they both can print to that printer. There is no other computer on the switch that they are on that is having this problem. Any suggestions or thoughts would be greatly appriciated. Thanks.