Well I got a protection program that runs and sees how protected your computer is, and well it ran and everything was good except for spyware wich i fixed and I had no wireless network protection. How would I go about protecting my wireless network? And also I've seen a guy in a car on his labtop outside of my house the past few days. Is there anyway I can tell if he has connected to it?

If you have a router then you can log onto the Admin interface and check the DHCP IP address allocation. Next time he is outside, just check to see (in the allocation table) how many addresses the router is giving out. If it is one - and you only have one PC on the network - then you're ok.

OK well now I know how to see if he is on it but now how would I go about protecting it?

Enable a WEP key. You will find this in the relevant section in your Router Admin control panel (probably under wireless security).

what type of Wireless router do you have?