How do I lock my wireless internet so neighbors can not log on

1. First you must set password to access the web interface, so that only you can change the setting.
For a linksys the default web-interface is at 192.168.1.1 The first term you access it enter username:admin, password admin. If that does not work read the manual to find that out.
2. Explore the TAB and each sub-menu to familiarize yourself with the interface. For change to Take effect you must SAVE. Button is at the bottom.
3. In the TAB SETUP>Basic Setup Activate the Automatic DHCP reservation of IP addresses. Enable it on the same page
4.Under the ADMINISTRATION TAB >Management enter a new router password.
5. Under the Wireless TAB> Security Menu, select the Security Mode as WPA2Personal, and Encyiption AES. Enter a passphrase ( like a password but can be a phrase -part of a sentence. For key renewal enter a number like 3600 seconds.
Save all.
Now if you connect a device through the wireless you will be prompted to enter the pass-phrase. You will be asked for it after every power down of router or reboot of router. If you reset the configuration by pressing the reset button on the router you must redo everything again.
Remember: You will erase everything every time you reset the router. So if you make mistakes, just reset it with a straightened paper clip.
Remember, any body who has physical access to the router can reset. If tech savvy, he/she can give him/her/self access.