Hello, if you can transform a router into an access point. Connect the router to the PC to change the internal settings. Open the CMD console and type ipconfig and in your browser in the address bar you put your default gateway IP which is something like 192.168.1.1 and it will ask you for username and password. Generally it is admin and 1234 or admin and admin, this depends on the model and brand. You can find this information on the internet. Once inside the configuration page locate a tab that says Network Setup or LAN Settings and change the IP Adress for example to 192.168.1.2. Then look where you can disable DHCP since this function will be fulfilled by the main router. Then look for the Wi-Fi tab that normally says Wireless Settings and give it a name and password that you can identify. Save the changes and you must connect your neighbor's modem cable to a LAN port of those where you would normally connect the PC and you can now use WiFi in your home. You should not use the WAN port at all.