Not sure what you mean by "I've tried it with file sharing turned on and off."
The first thing you need to do is ensure that each of the machines is a member of the same workgroup (Windows has a habit of automatically naming workgroups differently according to the OS version).
So, on each machine:
Right-click My Computer
Select the Computer Name tab
Click the Change button
Dot the Workgroup option
Choose a name for the workgoup and type it in, making sure it's identical on all machines.
Restart the machines.
Next, ensure that you've actually shared any folders that you want visible to others:
In Windows Explore, right-click a folder
Click Sharing and Security
Select the Sharing tab
In the middle section, check Share this folder on the network, and give it a share name, or accept the one that's suggested. Decide whether you want to be able to change files from other machines, and check the box accordingly.
You should now be able to see each of the machines and its shared folders from any other machine.
If you're using a firewall other than the Windows Firewall, you may also need to inform it that each of the machines is part of a trusted zone (how you do that depends on which firewall you have).