I'm not sure what you mean by "replaced my old Dell Windows Home 64bit with a new Windows Home 64bit". Do you mean that you reinstalled the operating system?
When you say you are unable to connect, I assume that means you have your Zen physically plugged into an available USB port. Do you see "Scott's Zen" in Computer? That's where I normally find my Zen listed. It also appears in devices and printers. Do you not see that?