But as it turned out one of my neighbors had an open Wi-Fi connection for some reason unknown. Unfortunately, I had two problems: first, none of my desktops had a Wi-Fi card and I only possessed one of those little USB wireless adapters. Secondly, the Wi-Fi signal was only reachable in my living room, far from my desktops.
So, what do we do in a situation like this? We turn one of our modems into an access point client, also known as WISP mode. The router in question is a TP-Link TL-WR543G. It's a pretty cheap model and you can't even install dd-wrt or openwrt on it due to it only accepting ROM sizes lower than 2MB but anyway, let's cut to the point.
What we're doing here is using the router's WISP operation mode to connect it to an open wireless connection. In this mode, the WAN port is disabled and all the LAN ports will share the open wireless connection IP address.
How to do it:
1. Reset your modem settings and set it to AP Client Router operation mode. You can also use the Wizard for this purpose if it suits you.
2. Now go into Wireless > Site Survey on the menu to the left. Let the router scan your site and find Wi-Fi access points. Find one that's open and suits you and choose Connect. The router will lead you to the Wireless Settings page.
4. We're done configuring the router. Connect all your desktop computers to the LAN ports and enjoy free (stolen) internet.
A word of advice:
Using open Wi-Fi connections puts you at risk. Who's to say the open Wi-Fi connection isn't a honeypot to attract unsuspecting people? Use a firewall to protect you and browse on secured websites. Don't use this connection to transfer sensitive data! You can use the HTTPS Everywhere extension or use a secure VPN. Free VPNs like HotSpot Shield also exist.