The simplest answer is to add a wireless adapter to your PC that doesn't have one. If it's a desktop you need a PCI card and if a Laptop a PC Card (PCMCIA). You could use a a USB adapter in either but they are not recommended.
Assuming that you have Ethernet adapters in both PCs you could connect them together and use the connected one's connection but by the time you buy a cross over cable and spend ages making it work. (This is assumed as you do not appear to have any computing skills.) you would be better off spending slightly more than the cross over cable on a wireless adapter.
BTW I shan't be looking at closed questions in future so it is important that you enter NEW question as as I said before.
t
September 2007