Help. i have not got any internet settings to connect to a network on my laptop.?

A few people have look through the laptop and can't find any program or anything already on the computer to search for a wireless network connection. Does anyone no any programs i could download that will search for wireless network and connect to them, i had one installed onto the laptop before but the laptop had to be rebooted and left it nothing on. help asap, i can't get on the internet from home.