Did you mean ad hoc (PC-PC) network? Since Windows Vista, 7 it is not able to connect automatically to ad hoc network. There is a couple of articles about how to connect to ad hoc network in Vista, Windows 7. It uses windows scheduler, but this solution not works for me just because you can't run scheduler every min, if other computer/printer or any other device was connected a bit later, for example. So I recommend you some specialized tool. Maxidix Wifi Suite, for examle can do it (my choice), and everything works as I would like it to. Here is short video www.youtube.com/watch?v=4TKZ1FfNrCE, and here is download link http://www.maxidix.com/products/wifi-suite.
Wish I help you.