Windows 7 32 bit computer does not show in network neighborhood

Question

If I go to Windows Explorer only certain computers will show (both Windows 7 32 bit and 64 bit computers) under network. Why would
another computer not be showing.
The computer is on Windows Server 2008 domain.
If I a computers that does not show and open Network and Sharing Center, Change advanced sharing settings, I see Turn on network discovery and Turn on file and printer sharing  are checked.

Answer 1

After upgrading all the computers on a small LAN (about 10 workstations) I found that only a few of the workstations would show up in network neighborhood.  This was a using a clean install of Windows7Pro on all the  computers.  After a great
deal of checking settings and verifying that the really could be accessed by mapping a drive to a known computer name and share such as:
\\SERVER1\data, but unable to see the computers in network neighborhood, out of frustration I changed the workgroup name from the default WORKGROUP to WORKGROUP1 and like magic the network neighborhood became populated. 
I saw hints about this in several other forums, but nothing on Microsoft, so wanted to pass it along that this really works.  OTH, I have other workgroups that work just fine with the default WORKGROUP name,
So, after changing all the computers in the workgroup over to WORKGROUP1 all became visible and my problem was solved.  Oh and this was just a typical TCP/IP network with a Dynex router providing dhcp services and internet access.  Absolutely plain
vanilla, no 3rd party firewalls, just the default tcp/ip network settings that are pretty much installed automatically when installing W7Pro.  And all the computers were set up as WORK networks with Network Discovery and sharing enabled.  I verified
again by changing some back to WORKGROUP that when I did so those computers were no longer visible on the network. 
Hope this helps someone else. 
Vern
vernonls