Connecting 3 PC's and a laptop using wifi?

you need network cables for the desktops (i imagine that you are talking about 3 desktops)

you need a router (wired into the modem with the internet port)

you may need WiFi to Ethernet adapters (as this would save you from buying a lot of huge long cables)

make sure you set the router up and then worry about the desktops your laptop will be your best friend until the desktops are wet up with the adapters basically, after you set up the router you set up the wifi adapters to connect wirelessly to your network. they have manuals and would be easier to follow them make sure you keep your ADMIN passwords in a secure space. you need to follow the manuals for your equipment i mentioned. it will make you have it easier then me having to type it up. make sure your wireless password is not OPEN always put a password so no one else can get into it but you.

if got wifi on your PC'c

>if you got windows 7/8

get internet running on Laptop with a LAN or over wifi , create ad-hoc conection and select let other users use internet, then connect all PC's with this wifi u will get net.

If no wifi on PC's

>Create a bridge connection using LAN on all of them, by just connecting them with each other using the cable to the one PC which has the internet , then bridge the new lan connection to your working net connection network .

>if on windows xp and PC's with wifi

Download connectify and create wifi network and connect PC's with them.

Buy a router, dumbass