Selecting specific computers in "Locations"

I have already setup a network between W7 x64 Ultimate machines. However, I am adding more computers to the network and would like to select as to which computers can see a particular folder. The problem is that when I am trying to set the permissions and go to "Locations," the only computer listed is mine, even though the "Network" folder clearly lists three other computers. How can I get these computers to also appear in "Locations" so I can choose which ones to share my files with? Ideally I am trying to create a new user group that will consist of preselected computers.

My only other option is to share the folder with every authenticated user on the network, which is not something I want to do. I'd like user X to get access while user Y be denied.

Thanks for any input.

make sure you have network discovery enabled and file sharing and for the particular folder that the permissions are correct

Armoth said:

make sure you have network discovery enabled and file sharing and for the particular folder that the permissions are correct

They are enabled. This is why when I go to "Networks" in my computer all computers are listed there. I am already sharing folders. But these computers do not appear in "Locations." Furthermore, I can't ping them in CMD. So I'm not sure what's wrong.

check ur firewall settings and confirm if file sharing is also enabled

Currently it is a homegroup, but I have tried both workgroup and homegroup. The homegroup actually gives you the option to enter a password to join all PCs together - I had issues with that password being accepted and timing out. Before I spend any time figuring this out for the homegroup, I wanted to make sure whether it even matters. I heard that workgroup is more robust and I want to go back to it.

I was suspecting my firewall too - I have Agnitum Outpost (windows firewall disabled), but I don't know if I need to enable specific ports. The best I can do is disable the firewall on two machines and see if they can see each other under "Locations."

And that's exactly what I'm trying to do: give access to computer X and deny access to computer Y, regardless of users.

sounds like it could be firewall related especially if it cannot reply to ur pings which are called icmp echo requests i believe under windows firewall but what ur doing is exactly what i would do disabled all firewalls and see if things start to light up