Can my HP 6656C Pavilion be setup for wireless?

I asked this question before, but don't think I provided clear information. OK, I have this old HP 6645C Pavilion, which I ran dia-up on a few years ago. I now have 3 new computers and they are setup on my home network with a router. I would like to connect the OLD HP to the network, but I don't know if it is capable. What do I check for and what do I need to connect it to the network. My new computers all run Windows XP and of course this old computer has old windows, but I don't know what else I need to determine if I can connect it to the network???????????????? I am a computer novice. So be gentle!