Okay, I need help.

I run on wireless internet [which is very laggy and annoying].
My computer internet refuses to work, and it's official pissing me off. I am being to forced to run off my neighbors internet while my parents have internet.

My Dad refuses to help me because he is a lazy ***** and I have only one choice:

To boot my computer.

I want to start over, but I don't have the CD [because this was given to me by a friend of my Dad's].

Is there anyway to do that on Vista? I need answers, because I am officialy hopeless at this point.