slavko
First
first
Windows 7 is a favorite, but most operating systems can handle a network.
Unless you want to set up a homegroup, a feature of windows 7, on your network you won't really need a windows 7 computer
Yes, network security should cover all aspects of the network. Whether it is online or off. Having more than one computer connected together increases your chances of having your computers being corrupted.
Home Network
Subnet mask defines our network bit . If we are using a single network then all computers should have same subnet mask as well as the ip address, that belongs to the same network id.
It does not matter, your network design and hardware is independent of the devices (hosts) that connect to it. Also, typically you can set up the network without using a computer, but even if you do require one, any computer will work, not necessarily one on Windows. You can use Linux, Windows, Mac OS X, etc. Any of them will work in a correctly designed computer network.
client-server network
I think it is depend upon network. You should consultant with any network expert.
To do that, an additional device is required, a network hub or a network switch, which all computers in the network segment should have to be connected to.
The setting for this should be under: Menu>Settings>Connectivity>Network