TD :
In chat you mentioned you have two PCs and your nephew lives within 100m.
A small ( 4-port or 8-port ) Ethernet hub will set you back about £50 - £60. Using straight-through RG45 cables, you can plug your PCs into this, and a cable to your nephew's PC will do. As long as the distance is less than 100m along the run of the cable, you should be ok. Of course you also need Ethernet cards for your PCs, but if they're reasonably new they may well be bundled or on the motherboard.
That's the hardware side. The software side is different. You may need to install TCP/IP on all machines, or just the Microsoft networking stuff. TCP/IP is easy once you've done it once, but that's easy for me to say as I do it all day every day.