The issue might be that sharing isn't enabled for both of the computers.
This could take me a while to type everything out, so I found a link to help navigate this a little easier. Try http://www.ehow.com/how_5030012_network-mac-pc.html This should get you setup to share items from one to the other. If that doesn't work, you might have to create an Ad Hoc network to get them to talk.
I have a PC and a MAC and want to setup a home network for accessing the files across the 2 computers.
They are connected to a wifi router. I tried the PING test. It's ok when I ping from the PC to the MAC, but not the other way. The firewall on the PC was turned off.
PC is running Vista, and MAC with OS X 10.9.5
Any help appreciated. Thanks