How I will add another set of computer and be able to link to an existing Internet?

Answer 1

You need a multi-port router. You can buy one fairly cheaply ($40) if you're not sharing a printer or about double that if you want a print server incorporated in the router.

Answer 2

You need a network interface card on each PC, but every modern PC has that (98% onboard). Resembles a phone input connector; only a bit wider.
Use a 4 or 8-port UTP-switch. You need two standard UTP-cables (CAT5); each PC uses 1 cable.
Alternatively (and cheaper): use a so-called 'UTP-cross cable' directly between the two PC's (but then you can't add more then two PC's to the network). You could be ready with about $3.
Then on one PC (where the (USB-)modem is connected to) 'share internet'. Assuming Windows XP:
http://en.wikipedia.org/wiki/Internet_Connection_Sharing
http://www.annoyances.org/exec/show/ics
http://www.microsoft.com/windowsxp/using/networking/expert/crawford_02july01.mspx

A (non-wireless!) router is an option too, but you don't need that if above option works.

Please stay away from wireless internet or wireless network: they are difficult to secure good enough; do not trust the manuals on that (that's all marketing). It's dangerous to have wireless, you're easily hacked without you know about it. MSN-chats can be picked up by anyone in the neighbourhood with wireless equipment. And this is just an example.

There are wireless security settings like 'only allow special mac-adresses'. Don't trust on that. These mac-adresses can be simulated on every wireless computer 25 (or more) yards away; and then they can abuse your internet connection or hack your computer without you ever know about it. Reading your email, passwords, creditcard number, etc.

Answer 3

The router is the way to go. If you already have the internet connection, then the router will be connected after the modem as in:

wall > modem > router > computers

You'll need to have one computer connected to the router to configure it and tell it how to make the modem connect to your ISP. Once that's done, the remaining computers can be pluged into the router or if it's wireless, they can connect that way provided they have wireless cards.

Answer 4

You need a hub or router depending on if this is wireless network . Exapmle If you have a cable modem you will need a Hub or router and then they can connect on the same workgroup with the same name. They all need to belong to the same workgroup.

Answer 5

A magic box called a router..

a switch will not work seeing how it uses node IP addresses to forward information.. but there is nothing to distribute an IP, weird huh..

Answer 6

Get a router and just plug it in.

Answer 7

Buy router.

Answer 8

a router is best way