Q: I can't get out of recovery mode!

I just bought an iPhone 4s second hand, and it was working fine until I tried to unlock it so it would work on my network. I did the usual steps to unlock it and connected it to iTunes. Nothing happened so I decided to update it to 7.1.2 hoping that'd make the unlock work. Anyway it wasn't done updating by the time I had to leave for work so I left it connected to the computer. I came back 8 hours later to find it still hadn't finished and wasn't going anywhere. the screen had the apple logo with a loading 'bar' beneath it that was just over half loaded. Anyway I unplugged it and the screen went dead. When I turn it on the apple logo comes up for a few seconds then it says connect to iTunes. When connected, iTunes tells me that it is in recovery mode and needs to be restored. I click okay, and it all looks good for a couple of minutes until it gets stuck at the same spot and says an unknown error occurred. I've tried pushing the home and power button, restarting my computer, and I also checked that I have the latest version of iTunes. None of these things helped though. Please let me know if you have any ideas as to how I can fix this!