Some Computers do not show up in the network list...

"We have a mixed environment including Windows 2008, 2008 R2, and 2012 servers. We also have WINS setup and configured on domain controllers. I do not understand why some servers and computers do not show up in the network list. One Server and some Computers are in the list, but the others aren’t..."

For the solution of this problem follow the steps below:

Go to the Primary Domain Controller and...
 

Enable NetBIOS over TCP/IP.

• Click “Start”, type “ncpa.cpl” into the search box for Windows Server 2008 and hit “Enter”.
• Right click on the “Local Area Connection” and select “Properties”.
• Click to select “Internet Protocol Version 4 (TCP/IPv4)”, and then click on “Properties” button.
• Click on “Advance” button, and then click on “WINS” tab.       
• Click to check “Enable NetBIOS over TCP/IP”, and then click “OK” and exit the settings.

Start “Computer Browser” service.

• Click “Start”, type “services” into the search box for Windows Server 2008 and hit “Enter”.
• Click on “Services (Local)”, and then click on “Standard” tab.
• Double click on “Computer Browser” service.
• On “Startup Type:” click to expand and select “Automatic”, and then click to “Apply” button.
• On “Service status:” click on “Start” button
• Now click “OK” and exit the settings.

Now you need restart the Server, after the Primary Domain Controller starting, you are available to see a list of all Servers and Computers in your network list J