Question : How to set up Wireless Home Network with Mcafee Firewall that is SAFE from public

I have a home network with 2 computers running Windows XP. McAfee Firewall is installed in both and I have marked each computer as being on a Trusted network. I connect to the internet via a wireless router. When I click on View Workgroup Computers on computer A, I can see the shared files and printers on Computer B. However, when I try to acess Computer A's files from computer B, I get "Workgroup is not accessible."

As far as I can see, my Network and Firewall settings are identical on both computers. In order for A to see B, computer B's Firewall has to have Microsoft Directory TCP port 445 open as well as Windows File Sharing TCP ports 137-139 open. However, B doesn't see A even if A has the same firewall settings. Why can't I access the Workgroup network from computer B?

Also, with the above mentioned ports open, and once the PCs are able to see each other's shared files, is my Home Network SAFE from public access to my files through the internet and router???

Answer : How to set up Wireless Home Network with Mcafee Firewall that is SAFE from public

No, Access by public is only granted if the public can get on your network either by plugging in their computer into an ethernet port on your router or by connecting wirelessly which in your case they will have to guess correctly or know the preshared key. This addresses the security portion, the other portion is as lobo79 pointed out that your mcafee firewall is not setup on computera to allow 445,135,137.139 connections.  Check whether you have your windows firewall enabled on one of the two systems.

IMHO, running a software firewall behind a router that has NAT functionality (i.e. your system does not get a public IP but gets one in the private ip range 10.0.0.0/8 172.16-31.255.255 172.16.0.0/12 192.168.0.0/16) is a waste of local system resources.