I've literally wasted nearly my whole Sunday messing with this. I'm attempting to restore my iPad so I can sell it. The iPad was jailbroken on 4.2.1 with GreenPoison. I tried to restore in iTunes earlier and it just got stuck on "preparing iPad for restore" for nearly an hour. I cancelled it and tried again. Same thing. Tried switching the USB plug it was using. Same thing. Tried the newest version of iTunes, same thing. I can't remember how many variations I tried but eventually I wound up with just a white screen. I fumbled around with DFU mode and got it back to the "connect to iTunes" screen on the iPad and tried again. Still no luck. So then I downloaded the 4.2.1 IPSW file from iClarified and tried to restore to 4.2.1 but kept getting error code 3194. So then I tried just a normal restore but keep getting error 1604. The error 3194 and error 1604 happen everytime on each method. If I leave the iPad on the "connect to iTunes screen" not plugged into anything it'll go to just an Apple logo after a few minutes. I'm about to pull my hair out. Does anybody have ANY fix or tips for this?