I'm sorry to hear it didn't work. It sounds like your computer is not recognizing the neo3do? Do you have the android adb drivers installed? I'm also using windows 7, but I have both the "android adb driver" and "google usb driver" installed previously for my other devices so perhaps those might help your computer recognize the neo3do.
If you are looking to root the nexus 7 consider Wugfresh toolkit - pretty nice tool I used to root my Gnexus. It also walks you through installation of necessary drivers.
For me the neo3do feels like a whole new device once rooted since I can now run adblock, autorun manager and uninstall some stock installed apps so that it runs much smoother. I was getting annoyed that I dropped $350 for it at first but now I"m pretty happy with it since it runs how I like. I haven't tried to overclock it since I don't play too many games or use cpu intensive programs much.
Good luck
FYI the other method I tried for my neo3do was oneclickroot - recognized the tablet but it couldn't root it.