Have you tried rebooting the netbook? If that doesn't work, maybe try reinstalling in case the driver didn't instal.. I didn't have to enter any code afaik, I just plugged it in and set who it was when it first synced.
As for the mac issue, you can always dual boot or use parallels, although I'm not too sure if it works in parallels as its been a while since I bothered downloading the data off mine. Either my omnipod or the dexcom wouldnt show up in a virtual copy of windows, but I'm leaning towards it being the omnipod. To do it on a mac you would basically need to buy a copy of windows to install.