Turn on the computer and click "start". Hover over the "Network connections" and click on the box "Show all connections". Highlight the icon for the network card to which you want to set a static IP address. Go to properties of that adapter.
Click with the left mouse button on the item "Internet Protocol TCP/IP" and click "Configure". After opening the new menu, highlight "Use the following IP address". In the first field enter the value IP assigned to this network adapter. Press Tab and look at the subnet mask value. It must be identical for all computers on your network.
If you need to configure the connection from your networked PC to the Internet, fill in the fields "Preferred DNS server" and "default gateway". Enter the address of the router or computer that connects to the Internet directly. Click "Apply". Close the settings menu and wait for the update of network settings.
Configure the network adapters of other computers. Use the IP addresses matching the first three segments. I.e., the IP format should look like the following: 100.100.100.XYZ. Do not use identical IPaddresses, so as not to cause a problem with the network. Check every time the value of the subnet mask. It should be the same for all network cards.
If the network includes devices capable of handing out IPaddresses, such as routers or switches, change the parameters of their work. Open the web interface settings of the necessary equipment. Go to the menu LAN. Look for DHCP, and disable this feature.
Make sure to restart the device after setting new parameters. Sometimes it is necessary to disconnect the equipment from AC power for a while.