Using ADB with usb debugging disabled, and no root
I had a similar problem.  I almost gave up and was like an inch from hard reset when something strange happened. When I connected the phone to USB as usual USB entry screen appeared, but I noticed that in this screen it is actually possible to lower the notificationbar and bingo &mdash; I was able to turn Wi-Fi ON.  And then I just entered my Google account info and the phone was unlocked.