GO TO COMPUTER that is NOT SHOWING in network
(This computer may properly show both computers in network and work correctly  -BUT do the following to that computer)
Tap on the Windows-key to open the Start Menu, or click on the Start Menu icon.
Type services.msc and double-click on the result. This opens the Services Manager on the computer.
Locate the following services and double-click on the service to open its properties.
Click in the "Startup type" menu and switch startup to Automatic (Delayed Start):
This following settings fixed all 3 of my computers..jt

Make sure that the following services are set to Automatic (Delayed Start):
DNS Client
Function Discovery Provider Host (FDPHost)
Function Discovery Resource Publication (FDResPub)
Network Connections (NetMan)  *
UPnP Device Host (UPnPHost)
Peer Name Resolution Protocol (PNRPSvc)
Peer Networking Grouping (P2PSvc)
Peer Networking Identity Manager (P2PIMSvc)
SSDP Discovery
Network Tip:  I had all kinds of problems with one computer not showing up in my network
I renamed the computer's name, and voila...the computer appeared.

BINGO...the missing computer showed up.
Windows 10 new feature:
Go to computer not showing in network
command prompt, see the IP address ( ie: Laptop is and (Desktop is
Go to other computer RUN  type---> \\\
1.Try this on computer NOT showing up --> open command prompt (admin) netsh winsock reset - then restart computer - if no good then:
2.Type netsh int ip reset
3.Type ipconfig /release
4.Type ipconfig /renew

CHANGE NETWORKED COMPUTERS' NAMES...name totally different

Windows 10 - You need permssion to perfom action network
After installing Homegroups, I couldnt copy files to my networked computers
Go to the folder on the computer you are trying to copy to...
Rt Click the folder, properties, Sharing, Click Share (even if it shows already shared)
Go to the Workgroup setting and Click for read/write permission
Go back to the Folder properties, and unclick read only...


Win 10 Networked computers not shown in Network?
Do a network RESET
Windows settings, All settings, Network & Internet,  Status,
scroll down to Network Reset  and allow time for the settings to propagate

Be certain both computers are on Private Networks
Windows settings, settings, Network & Internet, click on appropriate connection name,
Find the connection (ie: NETGEAR79, rt click it, Look for Network Profile, Private)

DHCP not enabled?
Unidentified network - No Internet Access - Ethernet

Start,  Network Connections. Right click on "Ethernet" (or whatever connection is being used) and left click on properties.
Scroll down to "Internet Protocol Version 4 (TCP/IP)" then click on Properties.
Local Area Connection Properties
Make sure the "Obtain an IP address automatically" and "Obtain DNS server address automatically" radio buttons are checked.
Be certain DHCP Enabled
Click OK.

Go to Control Panel, Network and Sharing Center, click
Connections, Ethernet (or whatever's in there) , Properties, scroll down to
UNCHECK Internet Protocol version v6.

This fixes the constant DHCP not enabled that windows will fix automatically with it's Troubleshooter....but stops constant alert messages
and Internet disconnections.