ok here's the deal in detail:
1. make sure every computer has a lan card
2. get a lan hub
3. using seperate pieces of lan cable (duh!) connect each computer to the hub
4. go to control panel >> network connections right click on local area network and click on properties
5. in the scroll menu click on Internet Protocol (TCP/IP)
6. click on properties
7. give all the computers successive IP addresses, such as 10.100.0.1, 10.100.0.2, 10.100.0.3 etc (make sure the first three sets of numbers match)
8. make sure the game in installed on every computer (i would suggest NFS. since most wanted might not work well on ur sys, try NFS Underground2. its quite interesting in multiplayer. also try some sports titles such as FIFA)
9. on any one computer, host the multiplayer game from the main menu of the game. give a sys name etc.
10. from other computers, join the game (from main-menu of the game) by selecting the host sys
thats it. enjoy yourself