If any firewalls are installed on any of the PCs, uninstall them.
This includes Zone Alarm, Sygate, Kerio, Norton Internet Security, Zero Knowledge Freedom, Cisco VPN Client, F-Secure, McAfee Firewall, Trend Micro, Comodo, PC Tools Firewall Plus etc.
In many cases, disabling the firewall is not enough; you have to actually uninstall it.
Do not install or re-install the firewall until after you have the network functioning properly.
Web Browser Settings
Internet Explorer 4.0 or Higher
Start IE web browser. Select-Tools-Internet Options-Connection Tab
In the “Connection” screen, there are three selections:
“Never dial a connection”,
“Dial whenever a network connection is not present”
“Always dial my default connection”.
If you can make a selection, select “Never dial a connection”.
If you cannot make a selection, select “LAN Settings”
Untick marks next to any of the displayed Options:
“Automatically detect settings”,
“Use automatic configuration script”
“Use a proxy server”.
Click “OK”. Then click “OK” again in the “Internet Options” page.
Network Adapter Setup on all Computers
Also called a LAN card (Local Area Network) or NIC card (Network Interface Connection)
Double-click on the “Network Connection”
Right-click on the “Local Area Connection” associated with your network adapter
Select “Properties” from the drop-down menu.
In the “Local Area Connection Properties” window all boxes should be ticked
At bottom of display tick the box “Show Icon in Notification Area When Connected
A display Icon will appear in the task bar when you have finish the setup
Click-Internet Protocol (TCP/IP) Click the “Properties” button
Select “Obtain an IP address automatically
Select “Obtain DNS server address automatically”
Click- Advanced-Click-WINS Tab-Tick-Enable LMHOSTS Lookup if untick
Do Not Change Any Other Setting
Your computer network card is now configured for use with the Modem/Router
Other Lan Card Setting
Right click on Local Area Connection Display Icon on task bar
At the top of display the type of Lan card will be displayed
Click Configure-Click-Advanced Tab
Click-Power Management Tab
Untick if selected "Allow Computer to turn this device off to save power
Network Connection Setting
Click-Start- Setting-Network Connection-New Connection Wizard
Select-Connect to the Internet-Next
Select-Set Up My Connection Manually-Next
Select-Connect using a broadband connection that is always on