USB: I couldn't and still can't connect my Smartphone by USB. (maybe something between win7-Android, drivers)
Wifi: Are you using wifi at home? why it stoped working for you?
when I go to some cafe and it be busy (lot people) then the internet is bad,
then I had (have) the same problem like you, installation is canceled just before it finish.
...try a simple "hello World" proyect